![\"Chalkboard-style](\"https:\/\/www.diagrams-ai.com\/wp-content\/uploads\/2026\/03\/dfd-vs-erd-system-design-infographic-chalkboard-style.jpg\"\/)
<\/figure>\n<\/div>\nHi\u1ec3u r\u00f5 S\u01a1 \u0111\u1ed3 D\u00f2ng D\u1eef li\u1ec7u (DFD) \ud83d\udd04<\/h2>\n
S\u01a1 \u0111\u1ed3 D\u00f2ng D\u1eef li\u1ec7u t\u1eadp trung v\u00e0o s\u1ef1 di chuy\u1ec3n c\u1ee7a d\u1eef li\u1ec7u qua m\u1ed9t h\u1ec7 th\u1ed1ng. N\u00f3 tr\u1ef1c quan h\u00f3a c\u00e1ch th\u00f4ng tin \u0111\u01b0\u1ee3c x\u1eed l\u00fd, chuy\u1ec3n \u0111\u1ed5i v\u00e0 l\u01b0u tr\u1eef. DFD kh\u00f4ng quan t\u00e2m \u0111\u1ebfn chi ti\u1ebft tri\u1ec3n khai v\u1eadt l\u00fd hay th\u1eddi gian th\u1ef1c hi\u1ec7n c\u00e1c qu\u00e1 tr\u00ecnh. Thay v\u00e0o \u0111\u00f3, n\u00f3 cung c\u1ea5p c\u00e1i nh\u00ecn c\u1ea5p cao v\u1ec1 lu\u1ed3ng logic c\u1ee7a th\u00f4ng tin.<\/p>\n
C\u00e1c th\u00e0nh ph\u1ea7n c\u1ed1t l\u00f5i c\u1ee7a DFD<\/h3>\n\n- C\u00e1c th\u1ef1c th\u1ec3 b\u00ean ngo\u00e0i:<\/strong> Ch\u00fang \u0111\u1ea1i di\u1ec7n cho ngu\u1ed3n ho\u1eb7c \u0111\u00edch c\u1ee7a d\u1eef li\u1ec7u n\u1eb1m ngo\u00e0i ranh gi\u1edbi h\u1ec7 th\u1ed1ng. Ch\u00fang c\u00f3 th\u1ec3 l\u00e0 ng\u01b0\u1eddi d\u00f9ng, c\u00e1c h\u1ec7 th\u1ed1ng kh\u00e1c ho\u1eb7c t\u1ed5 ch\u1ee9c. Ch\u00fang kh\u1edfi t\u1ea1o ho\u1eb7c nh\u1eadn d\u1eef li\u1ec7u nh\u01b0ng kh\u00f4ng x\u1eed l\u00fd d\u1eef li\u1ec7u \u0111\u00f3 trong b\u1ed1i c\u1ea3nh m\u00f4 h\u00ecnh c\u1ee5 th\u1ec3 n\u00e0y.<\/li>\n
- C\u00e1c qu\u00e1 tr\u00ecnh:<\/strong> \u0110\u01b0\u1ee3c bi\u1ec3u di\u1ec5n b\u1eb1ng c\u00e1c h\u00ecnh ch\u1eef nh\u1eadt tr\u00f2n, \u0111\u00e2y l\u00e0 c\u00e1c ho\u1ea1t \u0111\u1ed9ng bi\u1ebfn \u0111\u1ed5i d\u1eef li\u1ec7u \u0111\u1ea7u v\u00e0o th\u00e0nh d\u1eef li\u1ec7u \u0111\u1ea7u ra. M\u1ed9t qu\u00e1 tr\u00ecnh thay \u0111\u1ed5i tr\u1ea1ng th\u00e1i ho\u1eb7c d\u1ea1ng th\u1ee9c c\u1ee7a th\u00f4ng tin \u0111i qua n\u00f3. R\u1ea5t quan tr\u1ecdng l\u00e0 m\u1ed7i qu\u00e1 tr\u00ecnh ph\u1ea3i c\u00f3 \u00edt nh\u1ea5t m\u1ed9t \u0111\u1ea7u v\u00e0o v\u00e0 m\u1ed9t \u0111\u1ea7u ra.<\/li>\n
- C\u00e1c kho d\u1eef li\u1ec7u:<\/strong> \u0110\u00e2y l\u00e0 c\u00e1c kho l\u01b0u tr\u1eef n\u01a1i d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c gi\u1eef \u0111\u1ec3 s\u1eed d\u1ee5ng sau n\u00e0y. Trong DFD, ch\u00fang \u0111\u1ea1i di\u1ec7n cho c\u00e1c t\u1ec7p tin, c\u01a1 s\u1edf d\u1eef li\u1ec7u ho\u1eb7c l\u01b0u tr\u1eef. Ch\u00fang kh\u00f4ng ng\u1ee5 \u00fd m\u1ed9t c\u00f4ng ngh\u1ec7 c\u1ee5 th\u1ec3 m\u00e0 ch\u1ec9 \u0111\u01a1n thu\u1ea7n l\u00e0 s\u1ef1 t\u1ed3n t\u1ea1i c\u1ee7a b\u1ed9 nh\u1edb b\u1ec1n v\u1eefng.<\/li>\n
- C\u00e1c lu\u1ed3ng d\u1eef li\u1ec7u:<\/strong> \u0110\u01b0\u1ee3c bi\u1ec3u di\u1ec5n b\u1eb1ng c\u00e1c m\u0169i t\u00ean, ch\u00fang cho th\u1ea5y h\u01b0\u1edbng di chuy\u1ec3n c\u1ee7a d\u1eef li\u1ec7u. M\u1ed7i lu\u1ed3ng ph\u1ea3i \u0111\u01b0\u1ee3c ghi nh\u00e3n b\u1eb1ng t\u00ean c\u1ee7a g\u00f3i d\u1eef li\u1ec7u \u0111ang \u0111\u01b0\u1ee3c chuy\u1ec3n. C\u00e1c lu\u1ed3ng d\u1eef li\u1ec7u k\u1ebft n\u1ed1i c\u00e1c th\u1ef1c th\u1ec3, qu\u00e1 tr\u00ecnh v\u00e0 kho d\u1eef li\u1ec7u.<\/li>\n<\/ul>\n
C\u00e1c m\u1ee9c \u0111\u1ed9 tr\u1eebu t\u01b0\u1ee3ng<\/h3>\n
DFD th\u01b0\u1eddng \u0111\u01b0\u1ee3c t\u1ea1o theo c\u00e1ch ph\u00e2n c\u1ea5p \u0111\u1ec3 qu\u1ea3n l\u00fd \u0111\u1ed9 ph\u1ee9c t\u1ea1p:<\/p>\n
\n- S\u01a1 \u0111\u1ed3 b\u1ed1i c\u1ea3nh (M\u1ee9c 0):<\/strong> \u0110\u00e2y l\u00e0 c\u00e1i nh\u00ecn c\u1ea5p cao nh\u1ea5t. N\u00f3 th\u1ec3 hi\u1ec7n to\u00e0n b\u1ed9 h\u1ec7 th\u1ed1ng nh\u01b0 m\u1ed9t qu\u00e1 tr\u00ecnh duy nh\u1ea5t v\u00e0 x\u00e1c \u0111\u1ecbnh t\u1ea5t c\u1ea3 c\u00e1c th\u1ef1c th\u1ec3 b\u00ean ngo\u00e0i t\u01b0\u01a1ng t\u00e1c v\u1edbi n\u00f3. N\u00f3 x\u00e1c \u0111\u1ecbnh r\u00f5 ranh gi\u1edbi c\u1ee7a h\u1ec7 th\u1ed1ng.<\/li>\n
- S\u01a1 \u0111\u1ed3 m\u1ee9c 1:<\/strong> \u0110\u00e2y l\u00e0 vi\u1ec7c chia nh\u1ecf qu\u00e1 tr\u00ecnh duy nh\u1ea5t t\u1eeb s\u01a1 \u0111\u1ed3 b\u1ed1i c\u1ea3nh th\u00e0nh c\u00e1c qu\u00e1 tr\u00ecnh con ch\u00ednh. N\u00f3 cung c\u1ea5p th\u00eam chi ti\u1ebft v\u1ec1 c\u00e1ch h\u1ec7 th\u1ed1ng x\u1eed l\u00fd d\u1eef li\u1ec7u b\u00ean trong m\u00e0 kh\u00f4ng b\u1ecb m\u1eafc k\u1eb9t v\u00e0o logic ph\u1ee9c t\u1ea1p.<\/li>\n
- M\u1ee9c 2 v\u00e0 cao h\u01a1n:<\/strong> C\u00e1c s\u01a1 \u0111\u1ed3 n\u00e0y ph\u00e2n t\u00edch c\u1ee5 th\u1ec3 c\u00e1c qu\u00e1 tr\u00ecnh t\u1eeb m\u1ee9c 1 ra chi ti\u1ebft h\u01a1n. M\u1ee9c \u0111\u1ed9 n\u00e0y th\u01b0\u1eddng \u0111\u01b0\u1ee3c d\u00f9ng cho c\u00e1c module ph\u1ee9c t\u1ea1p, n\u01a1i c\u00e1c ph\u00e9p bi\u1ebfn \u0111\u1ed5i d\u1eef li\u1ec7u c\u1ee5 th\u1ec3 c\u1ea7n \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a ch\u1eb7t ch\u1ebd.<\/li>\n<\/ul>\n
Khi n\u00e0o n\u00ean \u00e1p d\u1ee5ng DFD<\/h3>\n
DFD hi\u1ec7u qu\u1ea3 nh\u1ea5t trong giai \u0111o\u1ea1n thu th\u1eadp y\u00eau c\u1ea7u v\u00e0 thi\u1ebft k\u1ebf ch\u1ee9c n\u0103ng. Ch\u00fang gi\u00fap c\u00e1c b\u00ean li\u00ean quan h\u00ecnh dung h\u00e0nh vi c\u1ee7a h\u1ec7 th\u1ed1ng m\u00e0 kh\u00f4ng b\u1ecb ph\u00e2n t\u00e2m b\u1edfi c\u00e1c r\u00e0ng bu\u1ed9c k\u1ef9 thu\u1eadt. Ch\u00fang \u0111\u1eb7c bi\u1ec7t h\u1eefu \u00edch cho:<\/p>\n
\n- Ph\u00e1t hi\u1ec7n c\u00e1c y\u00eau c\u1ea7u d\u1eef li\u1ec7u b\u1ecb thi\u1ebfu.<\/li>\n
- Truy\u1ec1n \u0111\u1ea1t c\u00e1c quy tr\u00ecnh kinh doanh \u0111\u1ebfn c\u00e1c b\u00ean li\u00ean quan kh\u00f4ng chuy\u00ean v\u1ec1 k\u1ef9 thu\u1eadt.<\/li>\n
- X\u00e1c \u0111\u1ecbnh ph\u1ea1m vi c\u1ee7a m\u1ed9t d\u1ef1 \u00e1n.<\/li>\n
- Ph\u00e2n t\u00edch an ninh th\u00f4ng tin b\u1eb1ng c\u00e1ch x\u00e1c \u0111\u1ecbnh n\u01a1i d\u1eef li\u1ec7u nh\u1ea1y c\u1ea3m \u0111i v\u00e0o v\u00e0 r\u1eddi kh\u1ecfi h\u1ec7 th\u1ed1ng.<\/li>\n<\/ul>\n
Hi\u1ec3u r\u00f5 S\u01a1 \u0111\u1ed3 Quan h\u1ec7 Th\u1ef1c th\u1ec3 (ERD) \ud83d\udd17<\/h2>\n
Trong khi DFD theo d\u00f5i s\u1ef1 di chuy\u1ec3n, th\u00ec S\u01a1 \u0111\u1ed3 Quan h\u1ec7 Th\u1ef1c th\u1ec3 l\u1ea1i t\u1eadp trung v\u00e0o c\u1ea5u tr\u00fac. ERD l\u00e0 m\u1ed9t m\u00f4 h\u00ecnh kh\u00e1i ni\u1ec7m \u0111\u01b0\u1ee3c d\u00f9ng \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh y\u00eau c\u1ea7u d\u1eef li\u1ec7u v\u00e0 c\u00e1c m\u1ed1i quan h\u1ec7 b\u00ean trong c\u01a1 s\u1edf d\u1eef li\u1ec7u. N\u00f3 m\u00f4 t\u1ea3 b\u1ea3n ch\u1ea5t t\u0129nh c\u1ee7a d\u1eef li\u1ec7u, \u0111\u1ea3m b\u1ea3o t\u00ednh to\u00e0n v\u1eb9n v\u00e0 chu\u1ea9n h\u00f3a.<\/p>\n
C\u00e1c th\u00e0nh ph\u1ea7n ch\u00ednh c\u1ee7a s\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3<\/h3>\n\n- C\u00e1c th\u1ef1c th\u1ec3:<\/strong>\u0110\u01b0\u1ee3c bi\u1ec3u di\u1ec5n d\u01b0\u1edbi d\u1ea1ng h\u00ecnh ch\u1eef nh\u1eadt, \u0111\u00e2y l\u00e0 c\u00e1c \u0111\u1ed1i t\u01b0\u1ee3ng ho\u1eb7c kh\u00e1i ni\u1ec7m trong th\u1ebf gi\u1edbi th\u1ef1c m\u00e0 d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c l\u01b0u tr\u1eef. C\u00e1c v\u00ed d\u1ee5 bao g\u1ed3m \u201cKh\u00e1ch h\u00e0ng,\u201d \u201c\u0110\u01a1n h\u00e0ng,\u201d ho\u1eb7c \u201cS\u1ea3n ph\u1ea9m.\u201d C\u00e1c th\u1ef1c th\u1ec3 l\u00e0 c\u00e1c kh\u1ed1i x\u00e2y d\u1ef1ng ch\u00ednh c\u1ee7a c\u1ea5u tr\u00fac d\u1eef li\u1ec7u.<\/li>\n
- Thu\u1ed9c t\u00ednh:<\/strong>\u0110\u00e2y l\u00e0 c\u00e1c thu\u1ed9c t\u00ednh ho\u1eb7c \u0111\u1eb7c \u0111i\u1ec3m c\u1ee7a m\u1ed9t th\u1ef1c th\u1ec3. Ch\u00fang th\u01b0\u1eddng \u0111\u01b0\u1ee3c li\u1ec7t k\u00ea b\u00ean trong h\u1ed9p th\u1ef1c th\u1ec3 ho\u1eb7c k\u1ebft n\u1ed1i v\u1edbi n\u00f3. C\u00e1c thu\u1ed9c t\u00ednh x\u00e1c \u0111\u1ecbnh c\u00e1c \u0111i\u1ec3m d\u1eef li\u1ec7u c\u1ee5 th\u1ec3, ch\u1eb3ng h\u1ea1n nh\u01b0 \u201cM\u00e3 kh\u00e1ch h\u00e0ng\u201d ho\u1eb7c \u201cNg\u00e0y \u0111\u1eb7t h\u00e0ng.\u201d M\u1ed9t s\u1ed1 thu\u1ed9c t\u00ednh \u0111\u00f3ng vai tr\u00f2 l\u00e0 kh\u00f3a ch\u00ednh, x\u00e1c \u0111\u1ecbnh duy nh\u1ea5t m\u1ed9t b\u1ea3n ghi.<\/li>\n
- M\u1ed1i quan h\u1ec7:<\/strong>\u0110\u01b0\u1ee3c bi\u1ec3u di\u1ec5n d\u01b0\u1edbi d\u1ea1ng h\u00ecnh thoi ho\u1eb7c \u0111\u01b0\u1eddng th\u1eb3ng, ch\u00fang x\u00e1c \u0111\u1ecbnh c\u00e1ch c\u00e1c th\u1ef1c th\u1ec3 t\u01b0\u01a1ng t\u00e1c v\u1edbi nhau. M\u1ed9t m\u1ed1i quan h\u1ec7 cho th\u1ea5y r\u1eb1ng m\u1ed9t b\u1ea3n ghi trong m\u1ed9t th\u1ef1c th\u1ec3 c\u00f3 li\u00ean h\u1ec7 v\u1edbi m\u1ed9t b\u1ea3n ghi trong th\u1ef1c th\u1ec3 kh\u00e1c.<\/li>\n
- S\u1ed1 l\u01b0\u1ee3ng (Cardinality):<\/strong>\u0110i\u1ec1u n\u00e0y x\u00e1c \u0111\u1ecbnh m\u1ed1i quan h\u1ec7 \u0111\u1ecbnh l\u01b0\u1ee3ng gi\u1eefa c\u00e1c th\u1ef1c th\u1ec3. C\u00e1c lo\u1ea1i cardinality ph\u1ed5 bi\u1ebfn bao g\u1ed3m M\u1ed9t-\u0111\u1ed1i-m\u1ed9t (1:1), M\u1ed9t-\u0111\u1ed1i-nhi\u1ec1u (1:N) v\u00e0 Nhi\u1ec1u-\u0111\u1ed1i-nhi\u1ec1u (M:N). Hi\u1ec3u r\u00f5 cardinality l\u00e0 r\u1ea5t quan tr\u1ecdng \u0111\u1ec3 ng\u0103n ng\u1eeba s\u1ef1 tr\u00f9ng l\u1eb7p d\u1eef li\u1ec7u.<\/li>\n<\/ul>\n
Chu\u1ea9n h\u00f3a v\u00e0 to\u00e0n v\u1eb9n d\u1eef li\u1ec7u<\/h3>\n
S\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3 th\u01b0\u1eddng l\u00e0 \u0111i\u1ec3m kh\u1edfi \u0111\u1ea7u cho qu\u00e1 tr\u00ecnh chu\u1ea9n h\u00f3a. Chu\u1ea9n h\u00f3a l\u00e0 qu\u00e1 tr\u00ecnh t\u1ed5 ch\u1ee9c d\u1eef li\u1ec7u nh\u1eb1m gi\u1ea3m thi\u1ec3u s\u1ef1 tr\u00f9ng l\u1eb7p v\u00e0 c\u1ea3i thi\u1ec7n to\u00e0n v\u1eb9n d\u1eef li\u1ec7u. S\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3 gi\u00fap h\u00ecnh dung s\u01a1 \u0111\u1ed3 logic tr\u01b0\u1edbc khi t\u1ea1o c\u00e1c b\u1ea3ng v\u1eadt l\u00fd. N\u00f3 \u0111\u1ea3m b\u1ea3o r\u1eb1ng:<\/p>\n
\n- D\u1eef li\u1ec7u kh\u00f4ng b\u1ecb tr\u00f9ng l\u1eb7p m\u1ed9t c\u00e1ch kh\u00f4ng c\u1ea7n thi\u1ebft.<\/li>\n
- To\u00e0n v\u1eb9n tham chi\u1ebfu \u0111\u01b0\u1ee3c duy tr\u00ec (v\u00ed d\u1ee5: m\u1ed9t \u0111\u01a1n h\u00e0ng kh\u00f4ng th\u1ec3 t\u1ed3n t\u1ea1i n\u1ebfu kh\u00f4ng c\u00f3 kh\u00e1ch h\u00e0ng).<\/li>\n
- C\u00e1c r\u00e0ng bu\u1ed9c nh\u01b0 t\u00ednh duy nh\u1ea5t v\u00e0 c\u00e1c tr\u01b0\u1eddng b\u1eaft bu\u1ed9c \u0111\u01b0\u1ee3c l\u00e0m r\u00f5.<\/li>\n<\/ul>\n
Khi n\u00e0o n\u00ean \u00e1p d\u1ee5ng s\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3<\/h3>\n
S\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3 l\u00e0 thi\u1ebft y\u1ebfu trong giai \u0111o\u1ea1n thi\u1ebft k\u1ebf c\u01a1 s\u1edf d\u1eef li\u1ec7u. Ch\u00fang t\u1ea1o ra s\u1ef1 k\u1ebft n\u1ed1i gi\u1eefa y\u00eau c\u1ea7u kinh doanh v\u00e0 tri\u1ec3n khai k\u1ef9 thu\u1eadt. Ch\u00fang \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng t\u1ed1t nh\u1ea5t khi:<\/p>\n
\n- Thi\u1ebft k\u1ebf l\u01b0\u1ee3c \u0111\u1ed3 cho c\u01a1 s\u1edf d\u1eef li\u1ec7u quan h\u1ec7.<\/li>\n
- X\u00e1c \u0111\u1ecbnh c\u00e1c r\u00e0ng bu\u1ed9c d\u1eef li\u1ec7u v\u00e0 quy t\u1eafc x\u00e1c th\u1ef1c.<\/li>\n
- \u0110\u1ea3m b\u1ea3o t\u00ednh nh\u1ea5t qu\u00e1n d\u1eef li\u1ec7u tr\u00ean to\u00e0n b\u1ed9 \u1ee9ng d\u1ee5ng.<\/li>\n
- L\u00ean k\u1ebf ho\u1ea1ch cho hi\u1ec7u qu\u1ea3 truy xu\u1ea5t d\u1eef li\u1ec7u v\u00e0 chi\u1ebfn l\u01b0\u1ee3c ch\u1ec9 m\u1ee5c h\u00f3a.<\/li>\n<\/ul>\n
S\u1ef1 kh\u00e1c bi\u1ec7t ch\u00ednh n\u1ed5i b\u1eadt \ud83c\udd9a<\/h2>\n
So s\u00e1nh hai m\u00f4 h\u00ecnh n\u00e0y c\u1ea1nh nhau l\u00e0m n\u1ed5i b\u1eadt m\u1ee5c \u0111\u00edch ri\u00eang bi\u1ec7t c\u1ee7a ch\u00fang. M\u1eb7c d\u00f9 ch\u00fang c\u00f3 th\u1ec3 tr\u00f4ng gi\u1ed1ng nhau v\u1ec1 \u0111\u1ed9 ph\u1ee9c t\u1ea1p h\u00ecnh \u1ea3nh, nh\u01b0ng m\u1ee5c \u0111\u00edch c\u1ee7a ch\u00fang l\u1ea1i kh\u00e1c bi\u1ec7t r\u00f5 r\u1ec7t.<\/p>\n
\n\n\nT\u00ednh n\u0103ng<\/th>\n S\u01a1 \u0111\u1ed3 lu\u1ed3ng d\u1eef li\u1ec7u (DFD)<\/th>\n S\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3 (ERD)<\/th>\n<\/tr>\n<\/thead>\n \n\nTr\u1ecdng t\u00e2m ch\u00ednh<\/strong><\/td>\nQuy tr\u00ecnh v\u00e0 di chuy\u1ec3n d\u1eef li\u1ec7u<\/td>\n C\u1ea5u tr\u00fac d\u1eef li\u1ec7u v\u00e0 m\u1ed1i quan h\u1ec7<\/td>\n<\/tr>\n \nTh\u00e0nh ph\u1ea7n th\u1eddi gian<\/strong><\/td>\n\u0110\u1ed9ng (th\u1ec3 hi\u1ec7n lu\u1ed3ng theo th\u1eddi gian)<\/td>\n T\u0129nh (hi\u1ec3n th\u1ecb c\u1ea5u tr\u00fac t\u1ea1i m\u1ed9t \u0111i\u1ec3m)<\/td>\n<\/tr>\n \nC\u00e2u h\u1ecfi ch\u00ednh<\/strong><\/td>\nD\u1eef li\u1ec7u di chuy\u1ec3n nh\u01b0 th\u1ebf n\u00e0o?<\/td>\n D\u1eef li\u1ec7u n\u00e0o \u0111\u01b0\u1ee3c l\u01b0u tr\u1eef v\u00e0 n\u00f3 \u0111\u01b0\u1ee3c li\u00ean k\u1ebft nh\u01b0 th\u1ebf n\u00e0o?<\/td>\n<\/tr>\n \n\u0110\u1ed1i t\u01b0\u1ee3ng m\u1ee5c ti\u00eau<\/strong><\/td>\nNh\u00e0 ph\u00e2n t\u00edch kinh doanh, c\u00e1c b\u00ean li\u00ean quan<\/td>\n Qu\u1ea3n tr\u1ecb vi\u00ean c\u01a1 s\u1edf d\u1eef li\u1ec7u, nh\u00e0 ph\u00e1t tri\u1ec3n ph\u00eda m\u00e1y ch\u1ee7<\/td>\n<\/tr>\n \nGiai \u0111o\u1ea1n v\u00f2ng \u0111\u1eddi<\/strong><\/td>\nY\u00eau c\u1ea7u, Thi\u1ebft k\u1ebf ch\u1ee9c n\u0103ng<\/td>\n Thi\u1ebft k\u1ebf c\u01a1 s\u1edf d\u1eef li\u1ec7u, Tri\u1ec3n khai<\/td>\n<\/tr>\n \nLogic so v\u1edbi L\u01b0u tr\u1eef<\/strong><\/td>\nT\u1eadp trung v\u00e0o Logic<\/td>\n T\u1eadp trung v\u00e0o L\u01b0u tr\u1eef<\/td>\n<\/tr>\n \n\u0110\u1ed9 ph\u1ee9c t\u1ea1p<\/strong><\/td>\nC\u00f3 th\u1ec3 ph\u1ee9c t\u1ea1p do nhi\u1ec1u lu\u1ed3ng<\/td>\n C\u00f3 th\u1ec3 ph\u1ee9c t\u1ea1p do c\u00e1c m\u1ed1i quan h\u1ec7<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\nKhi n\u00e0o n\u00ean \u01b0u ti\u00ean m\u00f4 h\u00ecnh h\u00f3a lu\u1ed3ng d\u1eef li\u1ec7u \ud83d\udcc9<\/h2>\n
C\u00f3 nh\u1eefng t\u00ecnh hu\u1ed1ng c\u1ee5 th\u1ec3 m\u00e0 s\u01a1 \u0111\u1ed3 lu\u1ed3ng d\u1eef li\u1ec7u (DFD) tr\u1edf th\u00e0nh c\u00f4ng c\u1ee5 ch\u00ednh cho thi\u1ebft k\u1ebf h\u1ec7 th\u1ed1ng. Vi\u1ec7c ch\u1ecdn DFD tr\u01b0\u1edbc th\u01b0\u1eddng l\u00e0 con \u0111\u01b0\u1eddng \u0111\u00fang \u0111\u1eafn khi logic kinh doanh l\u00e0 ph\u1ea7n ph\u1ee9c t\u1ea1p nh\u1ea5t c\u1ee7a h\u1ec7 th\u1ed1ng.<\/p>\n
\n- T\u1ef1 \u0111\u1ed9ng h\u00f3a quy tr\u00ecnh l\u00e0m vi\u1ec7c:<\/strong> N\u1ebfu h\u1ec7 th\u1ed1ng li\u00ean quan \u0111\u1ebfn c\u00e1c chu\u1ed7i ph\u00ea duy\u1ec7t ph\u1ee9c t\u1ea1p, thay \u0111\u1ed5i tr\u1ea1ng th\u00e1i ho\u1eb7c giao d\u1ecbch nhi\u1ec1u b\u01b0\u1edbc, s\u01a1 \u0111\u1ed3 lu\u1ed3ng d\u1eef li\u1ec7u (DFD) s\u1ebd l\u00e0m r\u00f5 tr\u00ecnh t\u1ef1 c\u00e1c thao t\u00e1c. N\u00f3 gi\u00fap x\u00e1c \u0111\u1ecbnh c\u00e1c \u0111i\u1ec3m ngh\u1ebdn trong quy tr\u00ecnh.<\/li>\n
- T\u00edch h\u1ee3p b\u00ean ngo\u00e0i:<\/strong> Khi m\u1ed9t h\u1ec7 th\u1ed1ng t\u01b0\u01a1ng t\u00e1c v\u1edbi nhi\u1ec1u API b\u00ean ngo\u00e0i ho\u1eb7c c\u00e1c h\u1ec7 th\u1ed1ng c\u0169, s\u01a1 \u0111\u1ed3 lu\u1ed3ng d\u1eef li\u1ec7u (DFD) gi\u00fap x\u00e1c \u0111\u1ecbnh c\u00e1c \u0111i\u1ec3m v\u00e0o v\u00e0 ra c\u1ee7a d\u1eef li\u1ec7u. N\u00f3 ng\u0103n ng\u1eeba m\u1ea5t d\u1eef li\u1ec7u trong qu\u00e1 tr\u00ecnh chuy\u1ec3n giao gi\u1eefa c\u00e1c h\u1ec7 th\u1ed1ng.<\/li>\n
- Ki\u1ec3m to\u00e1n b\u1ea3o m\u1eadt:<\/strong> C\u00e1c \u0111\u1ed9i b\u1ea3o m\u1eadt th\u01b0\u1eddng s\u1eed d\u1ee5ng DFD \u0111\u1ec3 theo d\u00f5i c\u00e1ch d\u1eef li\u1ec7u nh\u1ea1y c\u1ea3m di chuy\u1ec3n qua \u1ee9ng d\u1ee5ng. H\u1ecd c\u00f3 th\u1ec3 x\u00e1c \u0111\u1ecbnh c\u00e1c \u0111i\u1ec3m c\u1ea7n m\u00e3 h\u00f3a ho\u1eb7c n\u01a1i c\u1ea7n th\u1ef1c thi ki\u1ec3m so\u00e1t truy c\u1eadp.<\/li>\n
- T\u00e1i c\u1ea5u tr\u00fac quy tr\u00ecnh kinh doanh:<\/strong> Khi t\u1ed1i \u01b0u h\u00f3a c\u00e1c quy tr\u00ecnh hi\u1ec7n c\u00f3, DFD cung c\u1ea5p m\u1ed9t c\u01a1 s\u1edf tham chi\u1ebfu. B\u1ea1n c\u00f3 th\u1ec3 so s\u00e1nh quy tr\u00ecnh \u201cHi\u1ec7n t\u1ea1i\u201d v\u1edbi quy tr\u00ecnh \u201cT\u01b0\u01a1ng lai\u201d \u0111\u1ec3 \u0111o l\u01b0\u1eddng m\u1ee9c \u0111\u1ed9 c\u1ea3i thi\u1ec7n.<\/li>\n<\/ul>\n
Trong nh\u1eefng tr\u01b0\u1eddng h\u1ee3p n\u00e0y, t\u1eadp trung v\u00e0o ERD qu\u00e1 s\u1edbm c\u00f3 th\u1ec3 l\u00e0m m\u1edd \u0111i logic c\u1ee7a h\u1ec7 th\u1ed1ng. M\u1ed9t c\u01a1 s\u1edf d\u1eef li\u1ec7u c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c thi\u1ebft k\u1ebf ho\u00e0n h\u1ea3o, nh\u01b0ng n\u1ebfu lu\u1ed3ng quy tr\u00ecnh c\u00f3 v\u1ea5n \u0111\u1ec1, \u1ee9ng d\u1ee5ng s\u1ebd kh\u00f4ng \u0111\u00e1p \u1ee9ng \u0111\u01b0\u1ee3c nhu c\u1ea7u ng\u01b0\u1eddi d\u00f9ng.<\/p>\n
Khi n\u00e0o n\u00ean \u01b0u ti\u00ean m\u00f4 h\u00ecnh h\u00f3a c\u1ea5u tr\u00fac d\u1eef li\u1ec7u \ud83c\udfd7\ufe0f<\/h2>\n
Ng\u01b0\u1ee3c l\u1ea1i, c\u00f3 nh\u1eefng t\u00ecnh hu\u1ed1ng m\u00e0 t\u00ednh to\u00e0n v\u1eb9n v\u00e0 c\u1ea5u tr\u00fac d\u1eef li\u1ec7u l\u00e0 y\u1ebfu t\u1ed1 then ch\u1ed1t cho th\u00e0nh c\u00f4ng. ERD \u0111\u01b0\u1ee3c \u01b0u ti\u00ean khi kh\u1ed1i l\u01b0\u1ee3ng d\u1eef li\u1ec7u, c\u00e1c m\u1ed1i quan h\u1ec7 v\u00e0 r\u00e0ng bu\u1ed9c l\u00e0 y\u1ebfu t\u1ed1 th\u00fac \u0111\u1ea9y ch\u00ednh.<\/p>\n
\n- \u1ee8ng d\u1ee5ng d\u1eef li\u1ec7u l\u1edbn:<\/strong> Trong c\u00e1c h\u1ec7 th\u1ed1ng nh\u01b0 n\u1ec1n t\u1ea3ng ph\u00e2n t\u00edch ho\u1eb7c kho d\u1eef li\u1ec7u, c\u1ea5u tr\u00fac d\u1eef li\u1ec7u l\u00e0 \u0111i\u1ec1u quan tr\u1ecdng nh\u1ea5t. M\u1ed9t s\u01a1 \u0111\u1ed3 ERD \u0111\u1ea3m b\u1ea3o r\u1eb1ng l\u01b0\u1ee3c \u0111\u1ed3 h\u1ed7 tr\u1ee3 truy v\u1ea5n ph\u1ee9c t\u1ea1p v\u00e0 t\u00edch h\u1ee3p d\u1eef li\u1ec7u.<\/li>\n
- Di d\u1eddi h\u1ec7 th\u1ed1ng c\u0169:<\/strong> Khi di chuy\u1ec3n d\u1eef li\u1ec7u t\u1eeb h\u1ec7 th\u1ed1ng c\u0169 sang h\u1ec7 th\u1ed1ng m\u1edbi, vi\u1ec7c hi\u1ec3u r\u00f5 c\u00e1c m\u1ed1i quan h\u1ec7 hi\u1ec7n c\u00f3 l\u00e0 then ch\u1ed1t. S\u01a1 \u0111\u1ed3 ERD gi\u00fap \u00e1nh x\u1ea1 c\u00e1c b\u1ea3ng c\u0169 sang c\u1ea5u tr\u00fac m\u1edbi, \u0111\u1ea3m b\u1ea3o kh\u00f4ng c\u00f3 d\u1eef li\u1ec7u n\u00e0o b\u1ecb m\u1ea5t ho\u1eb7c h\u1ecfng.<\/li>\n
- Tu\u00e2n th\u1ee7 v\u00e0 qu\u1ea3n l\u00fd d\u1eef li\u1ec7u:<\/strong> C\u00e1c ng\u00e0nh nh\u01b0 t\u00e0i ch\u00ednh v\u00e0 y t\u1ebf y\u00eau c\u1ea7u qu\u1ea3n l\u00fd d\u1eef li\u1ec7u nghi\u00eam ng\u1eb7t. S\u01a1 \u0111\u1ed3 ERD ghi l\u1ea1i d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c l\u01b0u tr\u1eef \u1edf \u0111\u00e2u, ai l\u00e0 ng\u01b0\u1eddi s\u1edf h\u1eefu n\u00f3, v\u00e0 n\u00f3 li\u00ean quan \u0111\u1ebfn c\u00e1c \u0111i\u1ec3m d\u1eef li\u1ec7u kh\u00e1c nh\u01b0 th\u1ebf n\u00e0o, h\u1ed7 tr\u1ee3 b\u00e1o c\u00e1o tu\u00e2n th\u1ee7.<\/li>\n
- Y\u00eau c\u1ea7u hi\u1ec7u su\u1ea5t cao:<\/strong> N\u1ebfu h\u1ec7 th\u1ed1ng y\u00eau c\u1ea7u c\u00e1c thao t\u00e1c \u0111\u1ecdc\/ghi nhanh, s\u01a1 \u0111\u1ed3 ERD s\u1ebd \u0111\u1ecbnh h\u01b0\u1edbng chi\u1ebfn l\u01b0\u1ee3c ch\u1ec9 m\u1ee5c h\u00f3a v\u00e0 chia t\u00e1ch d\u1eef li\u1ec7u. Vi\u1ec7c hi\u1ec3u r\u00f5 c\u00e1c m\u1ed1i quan h\u1ec7 s\u1ebd gi\u00fap thi\u1ebft k\u1ebf c\u00e1c thao t\u00e1c n\u1ed1i (join) m\u1ed9t c\u00e1ch hi\u1ec7u qu\u1ea3.<\/li>\n<\/ul>\n
B\u1ecf qua s\u01a1 \u0111\u1ed3 ERD trong c\u00e1c t\u00ecnh hu\u1ed1ng n\u00e0y c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn m\u1ed9t c\u01a1 s\u1edf d\u1eef li\u1ec7u \u201cm\u1eafc c\u1ea1n\u201d v\u1edbi c\u00e1c b\u1ea3ng tr\u00f9ng l\u1eb7p, m\u1ed1i quan h\u1ec7 m\u01a1 h\u1ed3, v\u00e0 hi\u1ec7u su\u1ea5t suy gi\u1ea3m theo th\u1eddi gian.<\/p>\n
T\u00edch h\u1ee3p c\u1ea3 hai \u0111\u1ec3 x\u00e2y d\u1ef1ng ki\u1ebfn tr\u00fac v\u1eefng ch\u1eafc \ud83e\udd1d<\/h2>\n
M\u1eb7c d\u00f9 h\u1eefu \u00edch khi ph\u00e2n bi\u1ec7t gi\u1eefa DFD v\u00e0 ERD, nh\u01b0ng c\u00e1c h\u1ec7 th\u1ed1ng th\u00e0nh c\u00f4ng nh\u1ea5t th\u01b0\u1eddng s\u1eed d\u1ee5ng c\u1ea3 hai. Ch\u00fang b\u1ed5 sung cho nhau, ch\u1ee9 kh\u00f4ng lo\u1ea1i tr\u1eeb nhau. Quy tr\u00ecnh thi\u1ebft k\u1ebf h\u1ec7 th\u1ed1ng v\u1eefng ch\u1eafc th\u01b0\u1eddng \u0111i t\u1eeb lu\u1ed3ng d\u1eef li\u1ec7u \u0111\u1ebfn c\u1ea5u tr\u00fac.<\/p>\n
Ph\u01b0\u01a1ng ph\u00e1p tu\u1ea7n t\u1ef1<\/h3>\n\n- X\u00e1c \u0111\u1ecbnh ph\u1ea1m vi b\u1eb1ng DFD:<\/strong> B\u1eaft \u0111\u1ea7u b\u1eb1ng s\u01a1 \u0111\u1ed3 b\u1ed1i c\u1ea3nh \u0111\u1ec3 hi\u1ec3u r\u00f5 ranh gi\u1edbi. X\u00e1c \u0111\u1ecbnh t\u1ea5t c\u1ea3 c\u00e1c \u0111\u1ea7u v\u00e0o v\u00e0 \u0111\u1ea7u ra.<\/li>\n
- Ph\u00e2n t\u00edch c\u00e1c qu\u00e1 tr\u00ecnh:<\/strong> Ph\u00e2n t\u00e1ch c\u00e1c qu\u00e1 tr\u00ecnh \u0111\u1ec3 hi\u1ec3u r\u00f5 c\u00e1c ph\u00e9p bi\u1ebfn \u0111\u1ed5i d\u1eef li\u1ec7u c\u1ee5 th\u1ec3 c\u1ea7n thi\u1ebft.<\/li>\n
- X\u00e1c \u0111\u1ecbnh c\u00e1c th\u1ef1c th\u1ec3 d\u1eef li\u1ec7u:<\/strong> Khi ph\u00e2n t\u00edch lu\u1ed3ng d\u1eef li\u1ec7u, h\u00e3y x\u00e1c \u0111\u1ecbnh c\u00e1c \u0111\u1ed1i t\u01b0\u1ee3ng b\u1ec1n v\u1eefng \u0111ang \u0111\u01b0\u1ee3c di chuy\u1ec3n. Nh\u1eefng \u0111\u1ed1i t\u01b0\u1ee3ng n\u00e0y tr\u1edf th\u00e0nh c\u00e1c th\u1ef1c th\u1ec3 ti\u1ec1m n\u0103ng cho s\u01a1 \u0111\u1ed3 ERD.<\/li>\n
- Thi\u1ebft k\u1ebf s\u01a1 \u0111\u1ed3 ERD:<\/strong> T\u1ea1o s\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3 \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh c\u00e1ch c\u00e1c th\u1ef1c th\u1ec3 n\u00e0y \u0111\u01b0\u1ee3c l\u01b0u tr\u1eef v\u00e0 li\u00ean k\u1ebft v\u1edbi nhau.<\/li>\n
- X\u00e1c minh lu\u1ed3ng d\u1eef li\u1ec7u:<\/strong> \u00c1nh x\u1ea1 l\u1ea1i c\u00e1c lu\u1ed3ng d\u1eef li\u1ec7u v\u1ec1 c\u00e1c b\u1ea3ng c\u01a1 s\u1edf d\u1eef li\u1ec7u. \u0110\u1ea3m b\u1ea3o m\u1ed7i qu\u00e1 tr\u00ecnh trong DFD \u0111\u1ec1u c\u00f3 thao t\u00e1c l\u01b0u tr\u1eef t\u01b0\u01a1ng \u1ee9ng trong ERD.<\/li>\n<\/ol>\n
\u00c1nh x\u1ea1 c\u00e1c kho d\u1eef li\u1ec7u<\/h3>\n
Trong DFD, m\u1ed9t kho d\u1eef li\u1ec7u l\u00e0 m\u1ed9t ch\u1ed7 tr\u1ed1ng chung chung. Trong ERD, kho d\u1eef li\u1ec7u \u0111\u00f3 tr\u1edf th\u00e0nh \u0111\u1ecbnh ngh\u0129a b\u1ea3ng chi ti\u1ebft. Quy tr\u00ecnh \u00e1nh x\u1ea1 bao g\u1ed3m:<\/p>\n
\n- Chuy\u1ec3n \u0111\u1ed5i c\u00e1c kho d\u1eef li\u1ec7u DFD th\u00e0nh c\u00e1c th\u1ef1c th\u1ec3 ERD.<\/li>\n
- \u0110\u1ea3m b\u1ea3o t\u1ea5t c\u1ea3 c\u00e1c thu\u1ed9c t\u00ednh trong lu\u1ed3ng DFD \u0111\u1ec1u \u0111\u01b0\u1ee3c t\u00ednh \u0111\u1ebfn trong c\u00e1c thu\u1ed9c t\u00ednh ERD.<\/li>\n
- Ki\u1ec3m tra xem b\u1ed9i s\u1ed1 trong ERD c\u00f3 h\u1ed7 tr\u1ee3 b\u1ed9i s\u1ed1 c\u1ee7a c\u00e1c lu\u1ed3ng trong DFD hay kh\u00f4ng.<\/li>\n<\/ul>\n
V\u00ed d\u1ee5, n\u1ebfu DFD hi\u1ec3n th\u1ecb m\u1ed9t \u201cKh\u00e1ch h\u00e0ng\u201d g\u1eedi nhi\u1ec1u \u201c\u0110\u01a1n h\u00e0ng\u201d, th\u00ec ERD ph\u1ea3i ph\u1ea3n \u00e1nh m\u1ed1i quan h\u1ec7 M\u1ed9t-\u0110a gi\u1eefa th\u1ef1c th\u1ec3 Kh\u00e1ch h\u00e0ng v\u00e0 \u0110\u01a1n h\u00e0ng. N\u1ebfu DFD ng\u1ee5 \u00fd m\u1ed9t m\u1ed1i quan h\u1ec7 nhi\u1ec1u-\u0111a ph\u1ee9c t\u1ea1p (v\u00ed d\u1ee5: \u201cSinh vi\u00ean\u201d v\u00e0 \u201cKh\u00f3a h\u1ecdc\u201d), th\u00ec ERD ph\u1ea3i gi\u1edbi thi\u1ec7u m\u1ed9t th\u1ef1c th\u1ec3 li\u00ean k\u1ebft \u0111\u1ec3 gi\u1ea3i quy\u1ebft n\u00f3.<\/p>\n
Nh\u1eefng sai l\u1ea7m ph\u1ed5 bi\u1ebfn c\u1ea7n tr\u00e1nh \u26a0\ufe0f<\/h2>\n
L\u1eabn l\u1ed9n gi\u1eefa c\u00e1c m\u00f4 h\u00ecnh n\u00e0y ho\u1eb7c s\u1eed d\u1ee5ng sai c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn n\u1ee3 k\u1ef9 thu\u1eadt nghi\u00eam tr\u1ecdng. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 nh\u1eefng l\u1ed7i ph\u1ed5 bi\u1ebfn c\u1ea7n l\u01b0u \u00fd.<\/p>\n
1. L\u1eabn l\u1ed9n gi\u1eefa logic v\u00e0 l\u01b0u tr\u1eef<\/h3>\n
Kh\u00f4ng n\u00ean bao g\u1ed3m logic x\u1eed l\u00fd trong s\u01a1 \u0111\u1ed3 ERD. S\u01a1 \u0111\u1ed3 ERD n\u00ean \u0111\u1ecbnh ngh\u0129a c\u1ea5u tr\u00fac, ch\u1ee9 kh\u00f4ng ph\u1ea3i h\u00e0nh vi. N\u1ebfu b\u1ea1n nh\u1eadn th\u1ea5y m\u00ecnh \u0111ang v\u1ebd c\u00e1c m\u0169i t\u00ean \u0111\u1ea1i di\u1ec7n cho ‘x\u1eed l\u00fd’ trong ERD, c\u00f3 kh\u1ea3 n\u0103ng b\u1ea1n \u0111ang m\u00f4 t\u1ea3 DFD thay v\u00ec ERD.<\/p>\n
2. M\u00f4 h\u00ecnh h\u00f3a qu\u00e1 m\u1ee9c DFD<\/h3>\n
S\u01a1 \u0111\u1ed3 lu\u1ed3ng d\u1eef li\u1ec7u (DFD) kh\u00f4ng n\u00ean l\u00e0 s\u01a1 \u0111\u1ed3 l\u01b0u \u0111\u1ed3 c\u1ee7a m\u00e3 ngu\u1ed3n. N\u00f3 kh\u00f4ng n\u00ean chi ti\u1ebft t\u1eebng nh\u00e1nh \u0111i\u1ec1u ki\u1ec7n hay quy tr\u00ecnh x\u1eed l\u00fd l\u1ed7i. H\u00e3y gi\u1eef DFD \u1edf m\u1ee9c \u0111\u1ed9 logic. N\u1ebfu b\u1ea1n chi ti\u1ebft t\u1eebng c\u00e2u l\u1ec7nh ‘if-else’, s\u01a1 \u0111\u1ed3 s\u1ebd tr\u1edf n\u00ean kh\u00f3 \u0111\u1ecdc v\u00e0 m\u1ea5t \u0111i gi\u00e1 tr\u1ecb t\u1ed5ng quan c\u1ea5p cao.<\/p>\n
3. B\u1ecf qua t\u00ednh cardinality trong ERD<\/h3>\n
V\u1ebd c\u00e1c \u0111\u01b0\u1eddng n\u1ed1i gi\u1eefa c\u00e1c th\u1ef1c th\u1ec3 m\u00e0 kh\u00f4ng x\u00e1c \u0111\u1ecbnh cardinality l\u00e0 m\u1ed9t sai l\u1ea7m ph\u1ed5 bi\u1ebfn. M\u1ed9t \u0111\u01b0\u1eddng n\u1ed1i \u0111\u01a1n l\u1ebb kh\u00f4ng cho b\u1ea1n bi\u1ebft m\u1ed9t kh\u00e1ch h\u00e0ng c\u00f3 th\u1ec3 c\u00f3 0 \u0111\u01a1n h\u00e0ng hay m\u1ed9t tri\u1ec7u \u0111\u01a1n. Lu\u00f4n x\u00e1c \u0111\u1ecbnh r\u00f5 1:1, 1:N ho\u1eb7c M:N \u0111\u1ec3 tr\u00e1nh hi\u1ec3u nh\u1ea7m.<\/p>\n
4. B\u1ecf qua thu\u1ed9c t\u00ednh d\u1eef li\u1ec7u<\/h3>\n
C\u1ea3 hai s\u01a1 \u0111\u1ed3 \u0111\u1ec1u b\u1ecb \u1ea3nh h\u01b0\u1edfng khi c\u00e1c thu\u1ed9c t\u00ednh d\u1eef li\u1ec7u m\u01a1 h\u1ed3. Trong DFD, c\u00e1c lu\u1ed3ng ph\u1ea3i \u0111\u01b0\u1ee3c \u0111\u1eb7t t\u00ean m\u00f4 t\u1ea3 r\u00f5 r\u00e0ng (v\u00ed d\u1ee5: \u201cTh\u00f4ng tin thanh to\u00e1n \u0111\u00e3 x\u00e1c th\u1ef1c\u201d thay v\u00ec \u201cD\u1eef li\u1ec7u\u201d). Trong ERD, c\u00e1c thu\u1ed9c t\u00ednh n\u00ean x\u00e1c \u0111\u1ecbnh ki\u1ec3u d\u1eef li\u1ec7u v\u00e0 r\u00e0ng bu\u1ed9c khi c\u00f3 th\u1ec3.<\/p>\n
5. T\u1ea1o ra c\u00e1c qu\u00e1 tr\u00ecnh m\u1ed3 c\u00f4i<\/h3>\n
Trong DFD, m\u1ed9t qu\u00e1 tr\u00ecnh kh\u00f4ng th\u1ec3 t\u1ed3n t\u1ea1i n\u1ebfu kh\u00f4ng c\u00f3 d\u1eef li\u1ec7u ch\u1ea3y v\u00e0o ho\u1eb7c ra kh\u1ecfi n\u00f3. \u0110\u1ea3m b\u1ea3o m\u1ed7i h\u1ed9p qu\u00e1 tr\u00ecnh c\u00f3 \u00edt nh\u1ea5t m\u1ed9t lu\u1ed3ng v\u00e0o v\u00e0 m\u1ed9t lu\u1ed3ng ra. C\u00e1c qu\u00e1 tr\u00ecnh m\u1ed3 c\u00f4i cho th\u1ea5y logic ch\u1ebft ho\u1eb7c y\u00eau c\u1ea7u d\u1eef li\u1ec7u b\u1ecb thi\u1ebfu.<\/p>\n
C\u00e1c th\u1ef1c h\u00e0nh t\u1ed1t nh\u1ea5t cho t\u00e0i li\u1ec7u \ud83d\udcdd<\/h2>\n
\u0110\u1ec3 duy tr\u00ec s\u1ef1 r\u00f5 r\u00e0ng v\u00e0 h\u1eefu \u00edch, tu\u00e2n th\u1ee7 c\u00e1c ti\u00eau chu\u1ea9n t\u00e0i li\u1ec7u sau.<\/p>\n
\n- T\u00ean g\u1ecdi nh\u1ea5t qu\u00e1n:<\/strong>S\u1eed d\u1ee5ng c\u00f9ng m\u1ed9t thu\u1eadt ng\u1eef trong c\u1ea3 hai s\u01a1 \u0111\u1ed3. N\u1ebfu DFD g\u1ecdi n\u00f3 l\u00e0 \u201cKh\u00e1ch h\u00e0ng\u201d, th\u00ec ERD c\u0169ng n\u00ean g\u1ecdi l\u00e0 \u201cKh\u00e1ch h\u00e0ng\u201d, ch\u1ee9 kh\u00f4ng ph\u1ea3i \u201cNg\u01b0\u1eddi d\u00f9ng\u201d. T\u00ednh nh\u1ea5t qu\u00e1n gi\u00fap gi\u1ea3m t\u1ea3i nh\u1eadn th\u1ee9c cho \u0111\u1ed9i ng\u0169.<\/li>\n
- Ki\u1ec3m so\u00e1t phi\u00ean b\u1ea3n:<\/strong>Xem s\u01a1 \u0111\u1ed3 nh\u01b0 m\u00e3 ngu\u1ed3n. Duy tr\u00ec l\u1ecbch s\u1eed phi\u00ean b\u1ea3n. Khi h\u1ec7 th\u1ed1ng ph\u00e1t tri\u1ec3n, c\u00e1c s\u01a1 \u0111\u1ed3 ph\u1ea3i \u0111\u01b0\u1ee3c c\u1eadp nh\u1eadt \u0111\u1ec3 ph\u1ea3n \u00e1nh tr\u1ea1ng th\u00e1i hi\u1ec7n t\u1ea1i.<\/li>\n
- Ghi ch\u00fa b\u1ed1i c\u1ea3nh:<\/strong>Th\u00eam ch\u00fa th\u00edch v\u00e0o c\u00e1c khu v\u1ef1c ph\u1ee9c t\u1ea1p. N\u1ebfu m\u1ed9t m\u1ed1i quan h\u1ec7 kh\u00f4ng chu\u1ea9n, h\u00e3y gi\u1ea3i th\u00edch l\u00fd do. N\u1ebfu m\u1ed9t lu\u1ed3ng d\u1eef li\u1ec7u \u0111\u1ea1i di\u1ec7n cho m\u1ed9t c\u00f4ng vi\u1ec7c n\u1ec1n, h\u00e3y ghi ch\u00fa r\u1eb1ng n\u00f3 l\u00e0 b\u1ea5t \u0111\u1ed3ng b\u1ed9.<\/li>\n
- V\u00f2ng ki\u1ec3m tra:<\/strong>Th\u1ef1c hi\u1ec7n c\u00e1c cu\u1ed9c ki\u1ec3m tra ch\u00ednh th\u1ee9c v\u1edbi c\u1ea3 c\u00e1c b\u00ean li\u00ean quan v\u1ec1 kinh doanh (\u0111\u1ed1i v\u1edbi DFD) v\u00e0 c\u00e1c tr\u01b0\u1edfng nh\u00f3m k\u1ef9 thu\u1eadt (\u0111\u1ed1i v\u1edbi ERD). M\u1ed9t chuy\u00ean vi\u00ean ph\u00e2n t\u00edch kinh doanh c\u00f3 th\u1ec3 ph\u00e1t hi\u1ec7n l\u1ed7i logic trong DFD m\u00e0 m\u1ed9t l\u1eadp tr\u00ecnh vi\u00ean c\u00f3 th\u1ec3 b\u1ecf s\u00f3t, v\u00e0 ng\u01b0\u1ee3c l\u1ea1i.<\/li>\n<\/ul>\n
Suy ngh\u0129 cu\u1ed1i c\u00f9ng v\u1ec1 vi\u1ec7c l\u1ef1a ch\u1ecdn m\u00f4 h\u00ecnh \ud83e\udde0<\/h2>\n
Vi\u1ec7c l\u1ef1a ch\u1ecdn gi\u1eefa s\u01a1 \u0111\u1ed3 lu\u1ed3ng d\u1eef li\u1ec7u v\u00e0 s\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3 kh\u00f4ng ph\u1ea3i l\u00e0 vi\u1ec7c ch\u1ecdn m\u1ed9t trong hai m\u00e0 l\u00e0 ch\u1ecdn c\u00f4ng c\u1ee5 ph\u00f9 h\u1ee3p cho giai \u0111o\u1ea1n c\u1ee5 th\u1ec3 trong v\u00f2ng \u0111\u1eddi thi\u1ebft k\u1ebf. DFD l\u00e0m s\u00e1ng t\u1ecf con \u0111\u01b0\u1eddng d\u1eef li\u1ec7u \u0111i qua, \u0111\u1ea3m b\u1ea3o h\u1ec7 th\u1ed1ng ho\u1ea1t \u0111\u1ed9ng nh\u01b0 mong mu\u1ed1n. ERD c\u1ee7ng c\u1ed1 d\u1eef li\u1ec7u \u0111\u00f3, \u0111\u1ea3m b\u1ea3o d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c l\u01b0u tr\u1eef m\u1ed9t c\u00e1ch \u0111\u00e1ng tin c\u1eady v\u00e0 hi\u1ec7u qu\u1ea3.<\/p>\n
B\u1eb1ng c\u00e1ch n\u1eafm v\u1eefng m\u1ee5c \u0111\u00edch ri\u00eang bi\u1ec7t c\u1ee7a hai m\u00f4 h\u00ecnh n\u00e0y, c\u00e1c ki\u1ebfn tr\u00fac s\u01b0 c\u00f3 th\u1ec3 x\u00e2y d\u1ef1ng h\u1ec7 th\u1ed1ng v\u1eeba h\u1ee3p l\u00fd v\u1ec1 m\u1eb7t logic v\u1eeba v\u1eefng ch\u1eafc v\u1ec1 c\u1ea5u tr\u00fac. M\u1ee5c ti\u00eau kh\u00f4ng ph\u1ea3i l\u00e0 t\u1ea1o ra m\u1ed9t s\u01a1 \u0111\u1ed3 ho\u00e0n h\u1ea3o, m\u00e0 l\u00e0 t\u1ea1o ra s\u1ef1 hi\u1ec3u bi\u1ebft r\u00f5 r\u00e0ng v\u1ec1 h\u1ec7 th\u1ed1ng. Khi \u0111\u1ed9i ng\u0169 c\u00f3 th\u1ec3 nh\u00ecn v\u00e0o DFD v\u00e0 th\u1ea5y quy tr\u00ecnh, v\u00e0 nh\u00ecn v\u00e0o ERD v\u00e0 th\u1ea5y d\u1eef li\u1ec7u, n\u1ec1n t\u1ea3ng cho m\u1ed9t d\u1ef1 \u00e1n th\u00e0nh c\u00f4ng \u0111\u00e3 \u0111\u01b0\u1ee3c \u0111\u1eb7t v\u1eefng ch\u1eafc.<\/p>\n
H\u00e3y nh\u1edb r\u1eb1ng c\u00e1c m\u00f4 h\u00ecnh n\u00e0y l\u00e0 c\u00f4ng c\u1ee5 giao ti\u1ebfp. Gi\u00e1 tr\u1ecb c\u1ee7a ch\u00fang n\u1eb1m \u1edf s\u1ef1 hi\u1ec3u bi\u1ebft chung m\u00e0 ch\u00fang t\u1ea1o ra gi\u1eefa c\u00e1c th\u00e0nh vi\u00ean trong \u0111\u1ed9i. D\u00f9 b\u1ea1n \u0111ang v\u1ebd m\u1ed9t giao d\u1ecbch ph\u1ee9c t\u1ea1p hay \u0111\u1ecbnh ngh\u0129a h\u1ed3 s\u01a1 ng\u01b0\u1eddi d\u00f9ng, h\u00e3y lu\u00f4n t\u1eadp trung v\u00e0o s\u1ef1 r\u00f5 r\u00e0ng, \u0111\u1ed9 ch\u00ednh x\u00e1c v\u00e0 s\u1ef1 ph\u00f9 h\u1ee3p v\u1edbi m\u1ee5c ti\u00eau kinh doanh. V\u1edbi s\u1ef1 k\u1ebft h\u1ee3p \u0111\u00fang \u0111\u1eafn gi\u1eefa lu\u1ed3ng v\u00e0 c\u1ea5u tr\u00fac, thi\u1ebft k\u1ebf h\u1ec7 th\u1ed1ng tr\u1edf th\u00e0nh m\u1ed9t ngh\u1ec7 thu\u1eadt c\u00f3 k\u1ef7 lu\u1eadt thay v\u00ec m\u1ed9t tr\u00f2 ch\u01a1i suy \u0111o\u00e1n.<\/p>\n","protected":false},"excerpt":{"rendered":"
Thi\u1ebft k\u1ebf m\u1ed9t h\u1ec7 th\u1ed1ng ph\u1ea7n m\u1ec1m ph\u1ee9c t\u1ea1p \u0111\u00f2i h\u1ecfi b\u1ea3n \u0111\u1ed3 r\u00f5 r\u00e0ng v\u1ec1 c\u00e1ch d\u1eef li\u1ec7u di chuy\u1ec3n v\u00e0 n\u01a1i n\u00f3 \u0111\u01b0\u1ee3c l\u01b0u tr\u1eef. Kh\u00f4ng c\u00f3 c\u00e1ch ti\u1ebfp c\u1eadn c\u00f3 c\u1ea5u tr\u00fac, c\u00e1c ki\u1ebfn tr\u00fac c\u00f3 th\u1ec3 tr\u1edf n\u00ean mong manh, kh\u00f3 b\u1ea3o tr\u00ec v\u00e0 d\u1ec5 m\u1eafc l\u1ed7i logic. Hai k\u1ef9 thu\u1eadt m\u00f4 h\u00ecnh h\u00f3a n\u1ec1n t\u1ea3ng nh\u1ea5t trong k\u1ef9 thu\u1eadt h\u1ec7 th\u1ed1ng l\u00e0 S\u01a1 \u0111\u1ed3 D\u00f2ng D\u1eef li\u1ec7u (DFD) v\u00e0 S\u01a1 \u0111\u1ed3 Quan h\u1ec7 Th\u1ef1c th\u1ec3 (ERD). M\u1eb7c d\u00f9 c\u1ea3 hai \u0111\u1ec1u ph\u1ee5c v\u1ee5 ch\u1ee9c n\u0103ng quan tr\u1ecdng l\u00e0 tr\u1ef1c quan h\u00f3a, nh\u01b0ng ch\u00fang l\u1ea1i gi\u1ea3i quy\u1ebft nh\u1eefng kh\u00eda c\u1ea1nh c\u0103n b\u1ea3n kh\u00e1c nhau c\u1ee7a h\u1ec7 th\u1ed1ng. Hi\u1ec3u r\u00f5 s\u1ef1 kh\u00e1c bi\u1ec7t gi\u1eefa hai m\u00f4 h\u00ecnh n\u00e0y kh\u00f4ng ch\u1ec9 l\u00e0 m\u1ed9t b\u00e0i t\u1eadp h\u1ecdc thu\u1eadt; \u0111\u00f3 l\u00e0 nhu c\u1ea7u th\u1ef1c ti\u1ec5n \u0111\u1ed1i v\u1edbi c\u00e1c ki\u1ebfn tr\u00fac s\u01b0 h\u1ec7 th\u1ed1ng, chuy\u00ean vi\u00ean ph\u00e2n t\u00edch kinh doanh v\u00e0 nh\u00e0 ph\u00e1t tri\u1ec3n. Vi\u1ec7c s\u1eed d\u1ee5ng sai m\u00f4 h\u00ecnh \u1edf giai \u0111o\u1ea1n ph\u00e1t tri\u1ec3n kh\u00f4ng ph\u00f9 h\u1ee3p c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn hi\u1ec3u l\u1ea7m, hi\u1ec7u su\u1ea5t c\u01a1 s\u1edf d\u1eef li\u1ec7u k\u00e9m ho\u1eb7c logic kinh doanh b\u1ecb h\u1ecfng. H\u01b0\u1edbng d\u1eabn n\u00e0y kh\u00e1m ph\u00e1 nh\u1eefng n\u00e9t tinh t\u1ebf c\u1ee7a t\u1eebng lo\u1ea1i s\u01a1 \u0111\u1ed3, c\u00e1c th\u00e0nh ph\u1ea7n c\u1ee5 th\u1ec3 c\u1ee7a ch\u00fang, v\u00e0 c\u00e1c t\u00ecnh hu\u1ed1ng chi\u1ebfn l\u01b0\u1ee3c m\u00e0 m\u1ed9t m\u00f4 h\u00ecnh \u0111\u01b0\u1ee3c \u01b0u ti\u00ean h\u01a1n m\u00f4 h\u00ecnh kia. Hi\u1ec3u r\u00f5 S\u01a1 \u0111\u1ed3 D\u00f2ng D\u1eef li\u1ec7u (DFD) \ud83d\udd04 S\u01a1 \u0111\u1ed3 D\u00f2ng D\u1eef li\u1ec7u t\u1eadp trung v\u00e0o s\u1ef1 di chuy\u1ec3n c\u1ee7a d\u1eef li\u1ec7u qua m\u1ed9t h\u1ec7 th\u1ed1ng. N\u00f3 tr\u1ef1c quan h\u00f3a c\u00e1ch th\u00f4ng tin \u0111\u01b0\u1ee3c x\u1eed l\u00fd, chuy\u1ec3n \u0111\u1ed5i v\u00e0 l\u01b0u tr\u1eef. DFD kh\u00f4ng quan t\u00e2m \u0111\u1ebfn chi ti\u1ebft tri\u1ec3n khai v\u1eadt l\u00fd hay th\u1eddi gian th\u1ef1c hi\u1ec7n c\u00e1c qu\u00e1 tr\u00ecnh. Thay v\u00e0o \u0111\u00f3, n\u00f3 cung c\u1ea5p c\u00e1i nh\u00ecn c\u1ea5p cao v\u1ec1 lu\u1ed3ng logic c\u1ee7a th\u00f4ng tin. C\u00e1c th\u00e0nh ph\u1ea7n c\u1ed1t l\u00f5i c\u1ee7a DFD C\u00e1c th\u1ef1c th\u1ec3 b\u00ean ngo\u00e0i: Ch\u00fang \u0111\u1ea1i di\u1ec7n cho ngu\u1ed3n ho\u1eb7c \u0111\u00edch c\u1ee7a d\u1eef li\u1ec7u n\u1eb1m ngo\u00e0i ranh gi\u1edbi h\u1ec7 th\u1ed1ng. Ch\u00fang c\u00f3 th\u1ec3 l\u00e0 ng\u01b0\u1eddi d\u00f9ng, c\u00e1c h\u1ec7 th\u1ed1ng kh\u00e1c ho\u1eb7c t\u1ed5 ch\u1ee9c. Ch\u00fang kh\u1edfi t\u1ea1o ho\u1eb7c nh\u1eadn d\u1eef li\u1ec7u nh\u01b0ng kh\u00f4ng x\u1eed l\u00fd d\u1eef li\u1ec7u \u0111\u00f3 trong b\u1ed1i c\u1ea3nh m\u00f4 h\u00ecnh c\u1ee5 th\u1ec3 n\u00e0y. C\u00e1c qu\u00e1 tr\u00ecnh: \u0110\u01b0\u1ee3c bi\u1ec3u di\u1ec5n b\u1eb1ng c\u00e1c h\u00ecnh ch\u1eef nh\u1eadt tr\u00f2n, \u0111\u00e2y l\u00e0 c\u00e1c ho\u1ea1t \u0111\u1ed9ng bi\u1ebfn \u0111\u1ed5i d\u1eef li\u1ec7u \u0111\u1ea7u v\u00e0o th\u00e0nh d\u1eef li\u1ec7u \u0111\u1ea7u ra. M\u1ed9t qu\u00e1 tr\u00ecnh thay \u0111\u1ed5i tr\u1ea1ng th\u00e1i ho\u1eb7c d\u1ea1ng th\u1ee9c c\u1ee7a th\u00f4ng tin \u0111i qua n\u00f3. R\u1ea5t quan tr\u1ecdng l\u00e0 m\u1ed7i qu\u00e1 tr\u00ecnh ph\u1ea3i c\u00f3 \u00edt nh\u1ea5t m\u1ed9t \u0111\u1ea7u v\u00e0o v\u00e0 m\u1ed9t \u0111\u1ea7u ra. C\u00e1c kho d\u1eef li\u1ec7u: \u0110\u00e2y l\u00e0 c\u00e1c kho l\u01b0u tr\u1eef n\u01a1i d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c gi\u1eef \u0111\u1ec3 s\u1eed d\u1ee5ng sau n\u00e0y. Trong DFD, ch\u00fang \u0111\u1ea1i di\u1ec7n cho c\u00e1c t\u1ec7p tin, c\u01a1 s\u1edf d\u1eef li\u1ec7u ho\u1eb7c l\u01b0u tr\u1eef. Ch\u00fang kh\u00f4ng ng\u1ee5 \u00fd m\u1ed9t c\u00f4ng ngh\u1ec7 c\u1ee5 th\u1ec3 m\u00e0 ch\u1ec9 \u0111\u01a1n thu\u1ea7n l\u00e0 s\u1ef1 t\u1ed3n t\u1ea1i c\u1ee7a b\u1ed9 nh\u1edb b\u1ec1n v\u1eefng. C\u00e1c lu\u1ed3ng d\u1eef li\u1ec7u: \u0110\u01b0\u1ee3c bi\u1ec3u di\u1ec5n b\u1eb1ng c\u00e1c m\u0169i t\u00ean, ch\u00fang cho th\u1ea5y h\u01b0\u1edbng di chuy\u1ec3n c\u1ee7a d\u1eef li\u1ec7u. M\u1ed7i lu\u1ed3ng ph\u1ea3i \u0111\u01b0\u1ee3c ghi nh\u00e3n b\u1eb1ng t\u00ean c\u1ee7a g\u00f3i d\u1eef li\u1ec7u \u0111ang \u0111\u01b0\u1ee3c chuy\u1ec3n. C\u00e1c lu\u1ed3ng d\u1eef li\u1ec7u k\u1ebft n\u1ed1i c\u00e1c th\u1ef1c th\u1ec3, qu\u00e1 tr\u00ecnh v\u00e0 kho d\u1eef li\u1ec7u. C\u00e1c m\u1ee9c \u0111\u1ed9 tr\u1eebu t\u01b0\u1ee3ng DFD th\u01b0\u1eddng \u0111\u01b0\u1ee3c t\u1ea1o theo c\u00e1ch ph\u00e2n c\u1ea5p \u0111\u1ec3 qu\u1ea3n l\u00fd \u0111\u1ed9 ph\u1ee9c t\u1ea1p: S\u01a1 \u0111\u1ed3 b\u1ed1i c\u1ea3nh (M\u1ee9c 0): \u0110\u00e2y l\u00e0 c\u00e1i nh\u00ecn c\u1ea5p cao nh\u1ea5t. N\u00f3 th\u1ec3 hi\u1ec7n to\u00e0n b\u1ed9 h\u1ec7 th\u1ed1ng nh\u01b0 m\u1ed9t qu\u00e1 tr\u00ecnh duy nh\u1ea5t v\u00e0 x\u00e1c \u0111\u1ecbnh t\u1ea5t c\u1ea3 c\u00e1c th\u1ef1c th\u1ec3 b\u00ean ngo\u00e0i t\u01b0\u01a1ng t\u00e1c v\u1edbi n\u00f3. N\u00f3 x\u00e1c \u0111\u1ecbnh r\u00f5 ranh gi\u1edbi c\u1ee7a h\u1ec7 th\u1ed1ng. S\u01a1 \u0111\u1ed3 m\u1ee9c 1: \u0110\u00e2y l\u00e0 vi\u1ec7c chia nh\u1ecf qu\u00e1 tr\u00ecnh duy nh\u1ea5t t\u1eeb s\u01a1 \u0111\u1ed3 b\u1ed1i c\u1ea3nh th\u00e0nh c\u00e1c qu\u00e1 tr\u00ecnh con ch\u00ednh. N\u00f3 cung c\u1ea5p th\u00eam chi ti\u1ebft v\u1ec1 c\u00e1ch h\u1ec7 th\u1ed1ng x\u1eed l\u00fd d\u1eef li\u1ec7u b\u00ean trong m\u00e0 kh\u00f4ng b\u1ecb m\u1eafc k\u1eb9t v\u00e0o logic ph\u1ee9c t\u1ea1p. M\u1ee9c 2 v\u00e0 cao h\u01a1n: C\u00e1c s\u01a1 \u0111\u1ed3 n\u00e0y ph\u00e2n t\u00edch c\u1ee5 th\u1ec3 c\u00e1c qu\u00e1 tr\u00ecnh t\u1eeb m\u1ee9c 1 ra chi ti\u1ebft h\u01a1n. M\u1ee9c \u0111\u1ed9 n\u00e0y th\u01b0\u1eddng \u0111\u01b0\u1ee3c d\u00f9ng cho c\u00e1c module ph\u1ee9c t\u1ea1p, n\u01a1i c\u00e1c ph\u00e9p bi\u1ebfn \u0111\u1ed5i d\u1eef li\u1ec7u c\u1ee5 th\u1ec3 c\u1ea7n \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a ch\u1eb7t ch\u1ebd. Khi n\u00e0o n\u00ean \u00e1p d\u1ee5ng DFD DFD hi\u1ec7u qu\u1ea3 nh\u1ea5t trong giai \u0111o\u1ea1n thu th\u1eadp y\u00eau c\u1ea7u v\u00e0 thi\u1ebft k\u1ebf ch\u1ee9c n\u0103ng. Ch\u00fang gi\u00fap c\u00e1c b\u00ean li\u00ean quan h\u00ecnh dung h\u00e0nh vi c\u1ee7a h\u1ec7 th\u1ed1ng m\u00e0 kh\u00f4ng b\u1ecb ph\u00e2n t\u00e2m b\u1edfi c\u00e1c r\u00e0ng bu\u1ed9c k\u1ef9 thu\u1eadt. Ch\u00fang \u0111\u1eb7c bi\u1ec7t h\u1eefu \u00edch cho: Ph\u00e1t hi\u1ec7n c\u00e1c y\u00eau c\u1ea7u d\u1eef li\u1ec7u b\u1ecb thi\u1ebfu. Truy\u1ec1n \u0111\u1ea1t c\u00e1c quy tr\u00ecnh kinh doanh \u0111\u1ebfn c\u00e1c b\u00ean li\u00ean quan kh\u00f4ng chuy\u00ean v\u1ec1 k\u1ef9 thu\u1eadt. X\u00e1c \u0111\u1ecbnh ph\u1ea1m vi c\u1ee7a m\u1ed9t d\u1ef1 \u00e1n. Ph\u00e2n t\u00edch an ninh th\u00f4ng tin b\u1eb1ng c\u00e1ch x\u00e1c \u0111\u1ecbnh n\u01a1i d\u1eef li\u1ec7u nh\u1ea1y c\u1ea3m \u0111i v\u00e0o v\u00e0 r\u1eddi kh\u1ecfi h\u1ec7 th\u1ed1ng. Hi\u1ec3u r\u00f5 S\u01a1 \u0111\u1ed3 Quan h\u1ec7 Th\u1ef1c th\u1ec3 (ERD) \ud83d\udd17 Trong khi DFD theo d\u00f5i s\u1ef1 di chuy\u1ec3n, th\u00ec S\u01a1 \u0111\u1ed3 Quan h\u1ec7 Th\u1ef1c th\u1ec3 l\u1ea1i t\u1eadp trung v\u00e0o c\u1ea5u tr\u00fac. ERD l\u00e0 m\u1ed9t m\u00f4 h\u00ecnh kh\u00e1i ni\u1ec7m \u0111\u01b0\u1ee3c d\u00f9ng \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh y\u00eau c\u1ea7u d\u1eef li\u1ec7u v\u00e0 c\u00e1c m\u1ed1i quan h\u1ec7 b\u00ean trong c\u01a1 s\u1edf d\u1eef li\u1ec7u. N\u00f3 m\u00f4 t\u1ea3 b\u1ea3n ch\u1ea5t t\u0129nh c\u1ee7a d\u1eef li\u1ec7u, \u0111\u1ea3m b\u1ea3o t\u00ednh to\u00e0n v\u1eb9n v\u00e0 chu\u1ea9n h\u00f3a. C\u00e1c th\u00e0nh ph\u1ea7n ch\u00ednh c\u1ee7a s\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3 C\u00e1c th\u1ef1c th\u1ec3:\u0110\u01b0\u1ee3c bi\u1ec3u di\u1ec5n d\u01b0\u1edbi d\u1ea1ng h\u00ecnh ch\u1eef nh\u1eadt, \u0111\u00e2y l\u00e0 c\u00e1c \u0111\u1ed1i t\u01b0\u1ee3ng ho\u1eb7c kh\u00e1i ni\u1ec7m trong th\u1ebf gi\u1edbi th\u1ef1c m\u00e0 d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c l\u01b0u tr\u1eef. C\u00e1c v\u00ed d\u1ee5 bao g\u1ed3m \u201cKh\u00e1ch h\u00e0ng,\u201d \u201c\u0110\u01a1n h\u00e0ng,\u201d ho\u1eb7c \u201cS\u1ea3n ph\u1ea9m.\u201d C\u00e1c th\u1ef1c th\u1ec3 l\u00e0 c\u00e1c kh\u1ed1i x\u00e2y d\u1ef1ng ch\u00ednh c\u1ee7a c\u1ea5u tr\u00fac d\u1eef li\u1ec7u. Thu\u1ed9c t\u00ednh:\u0110\u00e2y l\u00e0 c\u00e1c thu\u1ed9c t\u00ednh ho\u1eb7c \u0111\u1eb7c \u0111i\u1ec3m c\u1ee7a m\u1ed9t th\u1ef1c th\u1ec3. Ch\u00fang th\u01b0\u1eddng \u0111\u01b0\u1ee3c li\u1ec7t k\u00ea b\u00ean trong h\u1ed9p th\u1ef1c th\u1ec3 ho\u1eb7c k\u1ebft n\u1ed1i v\u1edbi n\u00f3. C\u00e1c thu\u1ed9c t\u00ednh x\u00e1c \u0111\u1ecbnh c\u00e1c \u0111i\u1ec3m d\u1eef li\u1ec7u c\u1ee5 th\u1ec3, ch\u1eb3ng h\u1ea1n nh\u01b0 \u201cM\u00e3 kh\u00e1ch h\u00e0ng\u201d ho\u1eb7c \u201cNg\u00e0y \u0111\u1eb7t h\u00e0ng.\u201d M\u1ed9t s\u1ed1<\/p>\n","protected":false},"author":1,"featured_media":4239,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_yoast_wpseo_title":"DFD so v\u1edbi ERD: Khi n\u00e0o n\u00ean s\u1eed d\u1ee5ng t\u1eebng lo\u1ea1i trong thi\u1ebft k\u1ebf h\u1ec7 th\u1ed1ng","_yoast_wpseo_metadesc":"M\u1ed9t h\u01b0\u1edbng d\u1eabn to\u00e0n di\u1ec7n so s\u00e1nh s\u01a1 \u0111\u1ed3 lu\u1ed3ng d\u1eef li\u1ec7u v\u00e0 s\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3. H\u1ecdc c\u00e1ch khi n\u00e0o n\u00ean s\u1eed d\u1ee5ng DFD hay ERD \u0111\u1ec3 \u0111\u1ea1t \u0111\u01b0\u1ee3c ki\u1ebfn tr\u00fac h\u1ec7 th\u1ed1ng t\u1ed1i \u01b0u.","fifu_image_url":"","fifu_image_alt":"","footnotes":""},"categories":[84],"tags":[77,83],"class_list":["post-4238","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-dfd","tag-academic","tag-dfd"],"yoast_head":"\n
DFD so v\u1edbi ERD: Khi n\u00e0o n\u00ean s\u1eed d\u1ee5ng t\u1eebng lo\u1ea1i trong thi\u1ebft k\u1ebf h\u1ec7 th\u1ed1ng<\/title>\n<meta name=\"description\" content=\"M\u1ed9t h\u01b0\u1edbng d\u1eabn to\u00e0n di\u1ec7n so s\u00e1nh s\u01a1 \u0111\u1ed3 lu\u1ed3ng d\u1eef li\u1ec7u v\u00e0 s\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3. 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C\u00e1c m\u1ee9c \u0111\u1ed9 tr\u1eebu t\u01b0\u1ee3ng<\/h3>\n
DFD th\u01b0\u1eddng \u0111\u01b0\u1ee3c t\u1ea1o theo c\u00e1ch ph\u00e2n c\u1ea5p \u0111\u1ec3 qu\u1ea3n l\u00fd \u0111\u1ed9 ph\u1ee9c t\u1ea1p:<\/p>\n
- \n
- S\u01a1 \u0111\u1ed3 b\u1ed1i c\u1ea3nh (M\u1ee9c 0):<\/strong> \u0110\u00e2y l\u00e0 c\u00e1i nh\u00ecn c\u1ea5p cao nh\u1ea5t. N\u00f3 th\u1ec3 hi\u1ec7n to\u00e0n b\u1ed9 h\u1ec7 th\u1ed1ng nh\u01b0 m\u1ed9t qu\u00e1 tr\u00ecnh duy nh\u1ea5t v\u00e0 x\u00e1c \u0111\u1ecbnh t\u1ea5t c\u1ea3 c\u00e1c th\u1ef1c th\u1ec3 b\u00ean ngo\u00e0i t\u01b0\u01a1ng t\u00e1c v\u1edbi n\u00f3. N\u00f3 x\u00e1c \u0111\u1ecbnh r\u00f5 ranh gi\u1edbi c\u1ee7a h\u1ec7 th\u1ed1ng.<\/li>\n
- S\u01a1 \u0111\u1ed3 m\u1ee9c 1:<\/strong> \u0110\u00e2y l\u00e0 vi\u1ec7c chia nh\u1ecf qu\u00e1 tr\u00ecnh duy nh\u1ea5t t\u1eeb s\u01a1 \u0111\u1ed3 b\u1ed1i c\u1ea3nh th\u00e0nh c\u00e1c qu\u00e1 tr\u00ecnh con ch\u00ednh. N\u00f3 cung c\u1ea5p th\u00eam chi ti\u1ebft v\u1ec1 c\u00e1ch h\u1ec7 th\u1ed1ng x\u1eed l\u00fd d\u1eef li\u1ec7u b\u00ean trong m\u00e0 kh\u00f4ng b\u1ecb m\u1eafc k\u1eb9t v\u00e0o logic ph\u1ee9c t\u1ea1p.<\/li>\n
- M\u1ee9c 2 v\u00e0 cao h\u01a1n:<\/strong> C\u00e1c s\u01a1 \u0111\u1ed3 n\u00e0y ph\u00e2n t\u00edch c\u1ee5 th\u1ec3 c\u00e1c qu\u00e1 tr\u00ecnh t\u1eeb m\u1ee9c 1 ra chi ti\u1ebft h\u01a1n. M\u1ee9c \u0111\u1ed9 n\u00e0y th\u01b0\u1eddng \u0111\u01b0\u1ee3c d\u00f9ng cho c\u00e1c module ph\u1ee9c t\u1ea1p, n\u01a1i c\u00e1c ph\u00e9p bi\u1ebfn \u0111\u1ed5i d\u1eef li\u1ec7u c\u1ee5 th\u1ec3 c\u1ea7n \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a ch\u1eb7t ch\u1ebd.<\/li>\n<\/ul>\n
Khi n\u00e0o n\u00ean \u00e1p d\u1ee5ng DFD<\/h3>\n
DFD hi\u1ec7u qu\u1ea3 nh\u1ea5t trong giai \u0111o\u1ea1n thu th\u1eadp y\u00eau c\u1ea7u v\u00e0 thi\u1ebft k\u1ebf ch\u1ee9c n\u0103ng. Ch\u00fang gi\u00fap c\u00e1c b\u00ean li\u00ean quan h\u00ecnh dung h\u00e0nh vi c\u1ee7a h\u1ec7 th\u1ed1ng m\u00e0 kh\u00f4ng b\u1ecb ph\u00e2n t\u00e2m b\u1edfi c\u00e1c r\u00e0ng bu\u1ed9c k\u1ef9 thu\u1eadt. Ch\u00fang \u0111\u1eb7c bi\u1ec7t h\u1eefu \u00edch cho:<\/p>\n
- \n
- Ph\u00e1t hi\u1ec7n c\u00e1c y\u00eau c\u1ea7u d\u1eef li\u1ec7u b\u1ecb thi\u1ebfu.<\/li>\n
- Truy\u1ec1n \u0111\u1ea1t c\u00e1c quy tr\u00ecnh kinh doanh \u0111\u1ebfn c\u00e1c b\u00ean li\u00ean quan kh\u00f4ng chuy\u00ean v\u1ec1 k\u1ef9 thu\u1eadt.<\/li>\n
- X\u00e1c \u0111\u1ecbnh ph\u1ea1m vi c\u1ee7a m\u1ed9t d\u1ef1 \u00e1n.<\/li>\n
- Ph\u00e2n t\u00edch an ninh th\u00f4ng tin b\u1eb1ng c\u00e1ch x\u00e1c \u0111\u1ecbnh n\u01a1i d\u1eef li\u1ec7u nh\u1ea1y c\u1ea3m \u0111i v\u00e0o v\u00e0 r\u1eddi kh\u1ecfi h\u1ec7 th\u1ed1ng.<\/li>\n<\/ul>\n
Hi\u1ec3u r\u00f5 S\u01a1 \u0111\u1ed3 Quan h\u1ec7 Th\u1ef1c th\u1ec3 (ERD) \ud83d\udd17<\/h2>\n
Trong khi DFD theo d\u00f5i s\u1ef1 di chuy\u1ec3n, th\u00ec S\u01a1 \u0111\u1ed3 Quan h\u1ec7 Th\u1ef1c th\u1ec3 l\u1ea1i t\u1eadp trung v\u00e0o c\u1ea5u tr\u00fac. ERD l\u00e0 m\u1ed9t m\u00f4 h\u00ecnh kh\u00e1i ni\u1ec7m \u0111\u01b0\u1ee3c d\u00f9ng \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh y\u00eau c\u1ea7u d\u1eef li\u1ec7u v\u00e0 c\u00e1c m\u1ed1i quan h\u1ec7 b\u00ean trong c\u01a1 s\u1edf d\u1eef li\u1ec7u. N\u00f3 m\u00f4 t\u1ea3 b\u1ea3n ch\u1ea5t t\u0129nh c\u1ee7a d\u1eef li\u1ec7u, \u0111\u1ea3m b\u1ea3o t\u00ednh to\u00e0n v\u1eb9n v\u00e0 chu\u1ea9n h\u00f3a.<\/p>\n
C\u00e1c th\u00e0nh ph\u1ea7n ch\u00ednh c\u1ee7a s\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3<\/h3>\n
- \n
- C\u00e1c th\u1ef1c th\u1ec3:<\/strong>\u0110\u01b0\u1ee3c bi\u1ec3u di\u1ec5n d\u01b0\u1edbi d\u1ea1ng h\u00ecnh ch\u1eef nh\u1eadt, \u0111\u00e2y l\u00e0 c\u00e1c \u0111\u1ed1i t\u01b0\u1ee3ng ho\u1eb7c kh\u00e1i ni\u1ec7m trong th\u1ebf gi\u1edbi th\u1ef1c m\u00e0 d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c l\u01b0u tr\u1eef. C\u00e1c v\u00ed d\u1ee5 bao g\u1ed3m \u201cKh\u00e1ch h\u00e0ng,\u201d \u201c\u0110\u01a1n h\u00e0ng,\u201d ho\u1eb7c \u201cS\u1ea3n ph\u1ea9m.\u201d C\u00e1c th\u1ef1c th\u1ec3 l\u00e0 c\u00e1c kh\u1ed1i x\u00e2y d\u1ef1ng ch\u00ednh c\u1ee7a c\u1ea5u tr\u00fac d\u1eef li\u1ec7u.<\/li>\n
- Thu\u1ed9c t\u00ednh:<\/strong>\u0110\u00e2y l\u00e0 c\u00e1c thu\u1ed9c t\u00ednh ho\u1eb7c \u0111\u1eb7c \u0111i\u1ec3m c\u1ee7a m\u1ed9t th\u1ef1c th\u1ec3. Ch\u00fang th\u01b0\u1eddng \u0111\u01b0\u1ee3c li\u1ec7t k\u00ea b\u00ean trong h\u1ed9p th\u1ef1c th\u1ec3 ho\u1eb7c k\u1ebft n\u1ed1i v\u1edbi n\u00f3. C\u00e1c thu\u1ed9c t\u00ednh x\u00e1c \u0111\u1ecbnh c\u00e1c \u0111i\u1ec3m d\u1eef li\u1ec7u c\u1ee5 th\u1ec3, ch\u1eb3ng h\u1ea1n nh\u01b0 \u201cM\u00e3 kh\u00e1ch h\u00e0ng\u201d ho\u1eb7c \u201cNg\u00e0y \u0111\u1eb7t h\u00e0ng.\u201d M\u1ed9t s\u1ed1 thu\u1ed9c t\u00ednh \u0111\u00f3ng vai tr\u00f2 l\u00e0 kh\u00f3a ch\u00ednh, x\u00e1c \u0111\u1ecbnh duy nh\u1ea5t m\u1ed9t b\u1ea3n ghi.<\/li>\n
- M\u1ed1i quan h\u1ec7:<\/strong>\u0110\u01b0\u1ee3c bi\u1ec3u di\u1ec5n d\u01b0\u1edbi d\u1ea1ng h\u00ecnh thoi ho\u1eb7c \u0111\u01b0\u1eddng th\u1eb3ng, ch\u00fang x\u00e1c \u0111\u1ecbnh c\u00e1ch c\u00e1c th\u1ef1c th\u1ec3 t\u01b0\u01a1ng t\u00e1c v\u1edbi nhau. M\u1ed9t m\u1ed1i quan h\u1ec7 cho th\u1ea5y r\u1eb1ng m\u1ed9t b\u1ea3n ghi trong m\u1ed9t th\u1ef1c th\u1ec3 c\u00f3 li\u00ean h\u1ec7 v\u1edbi m\u1ed9t b\u1ea3n ghi trong th\u1ef1c th\u1ec3 kh\u00e1c.<\/li>\n
- S\u1ed1 l\u01b0\u1ee3ng (Cardinality):<\/strong>\u0110i\u1ec1u n\u00e0y x\u00e1c \u0111\u1ecbnh m\u1ed1i quan h\u1ec7 \u0111\u1ecbnh l\u01b0\u1ee3ng gi\u1eefa c\u00e1c th\u1ef1c th\u1ec3. C\u00e1c lo\u1ea1i cardinality ph\u1ed5 bi\u1ebfn bao g\u1ed3m M\u1ed9t-\u0111\u1ed1i-m\u1ed9t (1:1), M\u1ed9t-\u0111\u1ed1i-nhi\u1ec1u (1:N) v\u00e0 Nhi\u1ec1u-\u0111\u1ed1i-nhi\u1ec1u (M:N). Hi\u1ec3u r\u00f5 cardinality l\u00e0 r\u1ea5t quan tr\u1ecdng \u0111\u1ec3 ng\u0103n ng\u1eeba s\u1ef1 tr\u00f9ng l\u1eb7p d\u1eef li\u1ec7u.<\/li>\n<\/ul>\n
Chu\u1ea9n h\u00f3a v\u00e0 to\u00e0n v\u1eb9n d\u1eef li\u1ec7u<\/h3>\n
S\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3 th\u01b0\u1eddng l\u00e0 \u0111i\u1ec3m kh\u1edfi \u0111\u1ea7u cho qu\u00e1 tr\u00ecnh chu\u1ea9n h\u00f3a. Chu\u1ea9n h\u00f3a l\u00e0 qu\u00e1 tr\u00ecnh t\u1ed5 ch\u1ee9c d\u1eef li\u1ec7u nh\u1eb1m gi\u1ea3m thi\u1ec3u s\u1ef1 tr\u00f9ng l\u1eb7p v\u00e0 c\u1ea3i thi\u1ec7n to\u00e0n v\u1eb9n d\u1eef li\u1ec7u. S\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3 gi\u00fap h\u00ecnh dung s\u01a1 \u0111\u1ed3 logic tr\u01b0\u1edbc khi t\u1ea1o c\u00e1c b\u1ea3ng v\u1eadt l\u00fd. N\u00f3 \u0111\u1ea3m b\u1ea3o r\u1eb1ng:<\/p>\n
- \n
- D\u1eef li\u1ec7u kh\u00f4ng b\u1ecb tr\u00f9ng l\u1eb7p m\u1ed9t c\u00e1ch kh\u00f4ng c\u1ea7n thi\u1ebft.<\/li>\n
- To\u00e0n v\u1eb9n tham chi\u1ebfu \u0111\u01b0\u1ee3c duy tr\u00ec (v\u00ed d\u1ee5: m\u1ed9t \u0111\u01a1n h\u00e0ng kh\u00f4ng th\u1ec3 t\u1ed3n t\u1ea1i n\u1ebfu kh\u00f4ng c\u00f3 kh\u00e1ch h\u00e0ng).<\/li>\n
- C\u00e1c r\u00e0ng bu\u1ed9c nh\u01b0 t\u00ednh duy nh\u1ea5t v\u00e0 c\u00e1c tr\u01b0\u1eddng b\u1eaft bu\u1ed9c \u0111\u01b0\u1ee3c l\u00e0m r\u00f5.<\/li>\n<\/ul>\n
Khi n\u00e0o n\u00ean \u00e1p d\u1ee5ng s\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3<\/h3>\n
S\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3 l\u00e0 thi\u1ebft y\u1ebfu trong giai \u0111o\u1ea1n thi\u1ebft k\u1ebf c\u01a1 s\u1edf d\u1eef li\u1ec7u. Ch\u00fang t\u1ea1o ra s\u1ef1 k\u1ebft n\u1ed1i gi\u1eefa y\u00eau c\u1ea7u kinh doanh v\u00e0 tri\u1ec3n khai k\u1ef9 thu\u1eadt. Ch\u00fang \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng t\u1ed1t nh\u1ea5t khi:<\/p>\n
- \n
- Thi\u1ebft k\u1ebf l\u01b0\u1ee3c \u0111\u1ed3 cho c\u01a1 s\u1edf d\u1eef li\u1ec7u quan h\u1ec7.<\/li>\n
- X\u00e1c \u0111\u1ecbnh c\u00e1c r\u00e0ng bu\u1ed9c d\u1eef li\u1ec7u v\u00e0 quy t\u1eafc x\u00e1c th\u1ef1c.<\/li>\n
- \u0110\u1ea3m b\u1ea3o t\u00ednh nh\u1ea5t qu\u00e1n d\u1eef li\u1ec7u tr\u00ean to\u00e0n b\u1ed9 \u1ee9ng d\u1ee5ng.<\/li>\n
- L\u00ean k\u1ebf ho\u1ea1ch cho hi\u1ec7u qu\u1ea3 truy xu\u1ea5t d\u1eef li\u1ec7u v\u00e0 chi\u1ebfn l\u01b0\u1ee3c ch\u1ec9 m\u1ee5c h\u00f3a.<\/li>\n<\/ul>\n
S\u1ef1 kh\u00e1c bi\u1ec7t ch\u00ednh n\u1ed5i b\u1eadt \ud83c\udd9a<\/h2>\n
So s\u00e1nh hai m\u00f4 h\u00ecnh n\u00e0y c\u1ea1nh nhau l\u00e0m n\u1ed5i b\u1eadt m\u1ee5c \u0111\u00edch ri\u00eang bi\u1ec7t c\u1ee7a ch\u00fang. M\u1eb7c d\u00f9 ch\u00fang c\u00f3 th\u1ec3 tr\u00f4ng gi\u1ed1ng nhau v\u1ec1 \u0111\u1ed9 ph\u1ee9c t\u1ea1p h\u00ecnh \u1ea3nh, nh\u01b0ng m\u1ee5c \u0111\u00edch c\u1ee7a ch\u00fang l\u1ea1i kh\u00e1c bi\u1ec7t r\u00f5 r\u1ec7t.<\/p>\n
\n\n
\n \nT\u00ednh n\u0103ng<\/th>\n S\u01a1 \u0111\u1ed3 lu\u1ed3ng d\u1eef li\u1ec7u (DFD)<\/th>\n S\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3 (ERD)<\/th>\n<\/tr>\n<\/thead>\n \n Tr\u1ecdng t\u00e2m ch\u00ednh<\/strong><\/td>\n Quy tr\u00ecnh v\u00e0 di chuy\u1ec3n d\u1eef li\u1ec7u<\/td>\n C\u1ea5u tr\u00fac d\u1eef li\u1ec7u v\u00e0 m\u1ed1i quan h\u1ec7<\/td>\n<\/tr>\n \n Th\u00e0nh ph\u1ea7n th\u1eddi gian<\/strong><\/td>\n \u0110\u1ed9ng (th\u1ec3 hi\u1ec7n lu\u1ed3ng theo th\u1eddi gian)<\/td>\n T\u0129nh (hi\u1ec3n th\u1ecb c\u1ea5u tr\u00fac t\u1ea1i m\u1ed9t \u0111i\u1ec3m)<\/td>\n<\/tr>\n \n C\u00e2u h\u1ecfi ch\u00ednh<\/strong><\/td>\n D\u1eef li\u1ec7u di chuy\u1ec3n nh\u01b0 th\u1ebf n\u00e0o?<\/td>\n D\u1eef li\u1ec7u n\u00e0o \u0111\u01b0\u1ee3c l\u01b0u tr\u1eef v\u00e0 n\u00f3 \u0111\u01b0\u1ee3c li\u00ean k\u1ebft nh\u01b0 th\u1ebf n\u00e0o?<\/td>\n<\/tr>\n \n \u0110\u1ed1i t\u01b0\u1ee3ng m\u1ee5c ti\u00eau<\/strong><\/td>\n Nh\u00e0 ph\u00e2n t\u00edch kinh doanh, c\u00e1c b\u00ean li\u00ean quan<\/td>\n Qu\u1ea3n tr\u1ecb vi\u00ean c\u01a1 s\u1edf d\u1eef li\u1ec7u, nh\u00e0 ph\u00e1t tri\u1ec3n ph\u00eda m\u00e1y ch\u1ee7<\/td>\n<\/tr>\n \n Giai \u0111o\u1ea1n v\u00f2ng \u0111\u1eddi<\/strong><\/td>\n Y\u00eau c\u1ea7u, Thi\u1ebft k\u1ebf ch\u1ee9c n\u0103ng<\/td>\n Thi\u1ebft k\u1ebf c\u01a1 s\u1edf d\u1eef li\u1ec7u, Tri\u1ec3n khai<\/td>\n<\/tr>\n \n Logic so v\u1edbi L\u01b0u tr\u1eef<\/strong><\/td>\n T\u1eadp trung v\u00e0o Logic<\/td>\n T\u1eadp trung v\u00e0o L\u01b0u tr\u1eef<\/td>\n<\/tr>\n \n \u0110\u1ed9 ph\u1ee9c t\u1ea1p<\/strong><\/td>\n C\u00f3 th\u1ec3 ph\u1ee9c t\u1ea1p do nhi\u1ec1u lu\u1ed3ng<\/td>\n C\u00f3 th\u1ec3 ph\u1ee9c t\u1ea1p do c\u00e1c m\u1ed1i quan h\u1ec7<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Khi n\u00e0o n\u00ean \u01b0u ti\u00ean m\u00f4 h\u00ecnh h\u00f3a lu\u1ed3ng d\u1eef li\u1ec7u \ud83d\udcc9<\/h2>\n
C\u00f3 nh\u1eefng t\u00ecnh hu\u1ed1ng c\u1ee5 th\u1ec3 m\u00e0 s\u01a1 \u0111\u1ed3 lu\u1ed3ng d\u1eef li\u1ec7u (DFD) tr\u1edf th\u00e0nh c\u00f4ng c\u1ee5 ch\u00ednh cho thi\u1ebft k\u1ebf h\u1ec7 th\u1ed1ng. Vi\u1ec7c ch\u1ecdn DFD tr\u01b0\u1edbc th\u01b0\u1eddng l\u00e0 con \u0111\u01b0\u1eddng \u0111\u00fang \u0111\u1eafn khi logic kinh doanh l\u00e0 ph\u1ea7n ph\u1ee9c t\u1ea1p nh\u1ea5t c\u1ee7a h\u1ec7 th\u1ed1ng.<\/p>\n
- \n
- T\u1ef1 \u0111\u1ed9ng h\u00f3a quy tr\u00ecnh l\u00e0m vi\u1ec7c:<\/strong> N\u1ebfu h\u1ec7 th\u1ed1ng li\u00ean quan \u0111\u1ebfn c\u00e1c chu\u1ed7i ph\u00ea duy\u1ec7t ph\u1ee9c t\u1ea1p, thay \u0111\u1ed5i tr\u1ea1ng th\u00e1i ho\u1eb7c giao d\u1ecbch nhi\u1ec1u b\u01b0\u1edbc, s\u01a1 \u0111\u1ed3 lu\u1ed3ng d\u1eef li\u1ec7u (DFD) s\u1ebd l\u00e0m r\u00f5 tr\u00ecnh t\u1ef1 c\u00e1c thao t\u00e1c. N\u00f3 gi\u00fap x\u00e1c \u0111\u1ecbnh c\u00e1c \u0111i\u1ec3m ngh\u1ebdn trong quy tr\u00ecnh.<\/li>\n
- T\u00edch h\u1ee3p b\u00ean ngo\u00e0i:<\/strong> Khi m\u1ed9t h\u1ec7 th\u1ed1ng t\u01b0\u01a1ng t\u00e1c v\u1edbi nhi\u1ec1u API b\u00ean ngo\u00e0i ho\u1eb7c c\u00e1c h\u1ec7 th\u1ed1ng c\u0169, s\u01a1 \u0111\u1ed3 lu\u1ed3ng d\u1eef li\u1ec7u (DFD) gi\u00fap x\u00e1c \u0111\u1ecbnh c\u00e1c \u0111i\u1ec3m v\u00e0o v\u00e0 ra c\u1ee7a d\u1eef li\u1ec7u. N\u00f3 ng\u0103n ng\u1eeba m\u1ea5t d\u1eef li\u1ec7u trong qu\u00e1 tr\u00ecnh chuy\u1ec3n giao gi\u1eefa c\u00e1c h\u1ec7 th\u1ed1ng.<\/li>\n
- Ki\u1ec3m to\u00e1n b\u1ea3o m\u1eadt:<\/strong> C\u00e1c \u0111\u1ed9i b\u1ea3o m\u1eadt th\u01b0\u1eddng s\u1eed d\u1ee5ng DFD \u0111\u1ec3 theo d\u00f5i c\u00e1ch d\u1eef li\u1ec7u nh\u1ea1y c\u1ea3m di chuy\u1ec3n qua \u1ee9ng d\u1ee5ng. H\u1ecd c\u00f3 th\u1ec3 x\u00e1c \u0111\u1ecbnh c\u00e1c \u0111i\u1ec3m c\u1ea7n m\u00e3 h\u00f3a ho\u1eb7c n\u01a1i c\u1ea7n th\u1ef1c thi ki\u1ec3m so\u00e1t truy c\u1eadp.<\/li>\n
- T\u00e1i c\u1ea5u tr\u00fac quy tr\u00ecnh kinh doanh:<\/strong> Khi t\u1ed1i \u01b0u h\u00f3a c\u00e1c quy tr\u00ecnh hi\u1ec7n c\u00f3, DFD cung c\u1ea5p m\u1ed9t c\u01a1 s\u1edf tham chi\u1ebfu. B\u1ea1n c\u00f3 th\u1ec3 so s\u00e1nh quy tr\u00ecnh \u201cHi\u1ec7n t\u1ea1i\u201d v\u1edbi quy tr\u00ecnh \u201cT\u01b0\u01a1ng lai\u201d \u0111\u1ec3 \u0111o l\u01b0\u1eddng m\u1ee9c \u0111\u1ed9 c\u1ea3i thi\u1ec7n.<\/li>\n<\/ul>\n
Trong nh\u1eefng tr\u01b0\u1eddng h\u1ee3p n\u00e0y, t\u1eadp trung v\u00e0o ERD qu\u00e1 s\u1edbm c\u00f3 th\u1ec3 l\u00e0m m\u1edd \u0111i logic c\u1ee7a h\u1ec7 th\u1ed1ng. M\u1ed9t c\u01a1 s\u1edf d\u1eef li\u1ec7u c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c thi\u1ebft k\u1ebf ho\u00e0n h\u1ea3o, nh\u01b0ng n\u1ebfu lu\u1ed3ng quy tr\u00ecnh c\u00f3 v\u1ea5n \u0111\u1ec1, \u1ee9ng d\u1ee5ng s\u1ebd kh\u00f4ng \u0111\u00e1p \u1ee9ng \u0111\u01b0\u1ee3c nhu c\u1ea7u ng\u01b0\u1eddi d\u00f9ng.<\/p>\n
Khi n\u00e0o n\u00ean \u01b0u ti\u00ean m\u00f4 h\u00ecnh h\u00f3a c\u1ea5u tr\u00fac d\u1eef li\u1ec7u \ud83c\udfd7\ufe0f<\/h2>\n
Ng\u01b0\u1ee3c l\u1ea1i, c\u00f3 nh\u1eefng t\u00ecnh hu\u1ed1ng m\u00e0 t\u00ednh to\u00e0n v\u1eb9n v\u00e0 c\u1ea5u tr\u00fac d\u1eef li\u1ec7u l\u00e0 y\u1ebfu t\u1ed1 then ch\u1ed1t cho th\u00e0nh c\u00f4ng. ERD \u0111\u01b0\u1ee3c \u01b0u ti\u00ean khi kh\u1ed1i l\u01b0\u1ee3ng d\u1eef li\u1ec7u, c\u00e1c m\u1ed1i quan h\u1ec7 v\u00e0 r\u00e0ng bu\u1ed9c l\u00e0 y\u1ebfu t\u1ed1 th\u00fac \u0111\u1ea9y ch\u00ednh.<\/p>\n
- \n
- \u1ee8ng d\u1ee5ng d\u1eef li\u1ec7u l\u1edbn:<\/strong> Trong c\u00e1c h\u1ec7 th\u1ed1ng nh\u01b0 n\u1ec1n t\u1ea3ng ph\u00e2n t\u00edch ho\u1eb7c kho d\u1eef li\u1ec7u, c\u1ea5u tr\u00fac d\u1eef li\u1ec7u l\u00e0 \u0111i\u1ec1u quan tr\u1ecdng nh\u1ea5t. M\u1ed9t s\u01a1 \u0111\u1ed3 ERD \u0111\u1ea3m b\u1ea3o r\u1eb1ng l\u01b0\u1ee3c \u0111\u1ed3 h\u1ed7 tr\u1ee3 truy v\u1ea5n ph\u1ee9c t\u1ea1p v\u00e0 t\u00edch h\u1ee3p d\u1eef li\u1ec7u.<\/li>\n
- Di d\u1eddi h\u1ec7 th\u1ed1ng c\u0169:<\/strong> Khi di chuy\u1ec3n d\u1eef li\u1ec7u t\u1eeb h\u1ec7 th\u1ed1ng c\u0169 sang h\u1ec7 th\u1ed1ng m\u1edbi, vi\u1ec7c hi\u1ec3u r\u00f5 c\u00e1c m\u1ed1i quan h\u1ec7 hi\u1ec7n c\u00f3 l\u00e0 then ch\u1ed1t. S\u01a1 \u0111\u1ed3 ERD gi\u00fap \u00e1nh x\u1ea1 c\u00e1c b\u1ea3ng c\u0169 sang c\u1ea5u tr\u00fac m\u1edbi, \u0111\u1ea3m b\u1ea3o kh\u00f4ng c\u00f3 d\u1eef li\u1ec7u n\u00e0o b\u1ecb m\u1ea5t ho\u1eb7c h\u1ecfng.<\/li>\n
- Tu\u00e2n th\u1ee7 v\u00e0 qu\u1ea3n l\u00fd d\u1eef li\u1ec7u:<\/strong> C\u00e1c ng\u00e0nh nh\u01b0 t\u00e0i ch\u00ednh v\u00e0 y t\u1ebf y\u00eau c\u1ea7u qu\u1ea3n l\u00fd d\u1eef li\u1ec7u nghi\u00eam ng\u1eb7t. S\u01a1 \u0111\u1ed3 ERD ghi l\u1ea1i d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c l\u01b0u tr\u1eef \u1edf \u0111\u00e2u, ai l\u00e0 ng\u01b0\u1eddi s\u1edf h\u1eefu n\u00f3, v\u00e0 n\u00f3 li\u00ean quan \u0111\u1ebfn c\u00e1c \u0111i\u1ec3m d\u1eef li\u1ec7u kh\u00e1c nh\u01b0 th\u1ebf n\u00e0o, h\u1ed7 tr\u1ee3 b\u00e1o c\u00e1o tu\u00e2n th\u1ee7.<\/li>\n
- Y\u00eau c\u1ea7u hi\u1ec7u su\u1ea5t cao:<\/strong> N\u1ebfu h\u1ec7 th\u1ed1ng y\u00eau c\u1ea7u c\u00e1c thao t\u00e1c \u0111\u1ecdc\/ghi nhanh, s\u01a1 \u0111\u1ed3 ERD s\u1ebd \u0111\u1ecbnh h\u01b0\u1edbng chi\u1ebfn l\u01b0\u1ee3c ch\u1ec9 m\u1ee5c h\u00f3a v\u00e0 chia t\u00e1ch d\u1eef li\u1ec7u. Vi\u1ec7c hi\u1ec3u r\u00f5 c\u00e1c m\u1ed1i quan h\u1ec7 s\u1ebd gi\u00fap thi\u1ebft k\u1ebf c\u00e1c thao t\u00e1c n\u1ed1i (join) m\u1ed9t c\u00e1ch hi\u1ec7u qu\u1ea3.<\/li>\n<\/ul>\n
B\u1ecf qua s\u01a1 \u0111\u1ed3 ERD trong c\u00e1c t\u00ecnh hu\u1ed1ng n\u00e0y c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn m\u1ed9t c\u01a1 s\u1edf d\u1eef li\u1ec7u \u201cm\u1eafc c\u1ea1n\u201d v\u1edbi c\u00e1c b\u1ea3ng tr\u00f9ng l\u1eb7p, m\u1ed1i quan h\u1ec7 m\u01a1 h\u1ed3, v\u00e0 hi\u1ec7u su\u1ea5t suy gi\u1ea3m theo th\u1eddi gian.<\/p>\n
T\u00edch h\u1ee3p c\u1ea3 hai \u0111\u1ec3 x\u00e2y d\u1ef1ng ki\u1ebfn tr\u00fac v\u1eefng ch\u1eafc \ud83e\udd1d<\/h2>\n
M\u1eb7c d\u00f9 h\u1eefu \u00edch khi ph\u00e2n bi\u1ec7t gi\u1eefa DFD v\u00e0 ERD, nh\u01b0ng c\u00e1c h\u1ec7 th\u1ed1ng th\u00e0nh c\u00f4ng nh\u1ea5t th\u01b0\u1eddng s\u1eed d\u1ee5ng c\u1ea3 hai. Ch\u00fang b\u1ed5 sung cho nhau, ch\u1ee9 kh\u00f4ng lo\u1ea1i tr\u1eeb nhau. Quy tr\u00ecnh thi\u1ebft k\u1ebf h\u1ec7 th\u1ed1ng v\u1eefng ch\u1eafc th\u01b0\u1eddng \u0111i t\u1eeb lu\u1ed3ng d\u1eef li\u1ec7u \u0111\u1ebfn c\u1ea5u tr\u00fac.<\/p>\n
Ph\u01b0\u01a1ng ph\u00e1p tu\u1ea7n t\u1ef1<\/h3>\n
- \n
- X\u00e1c \u0111\u1ecbnh ph\u1ea1m vi b\u1eb1ng DFD:<\/strong> B\u1eaft \u0111\u1ea7u b\u1eb1ng s\u01a1 \u0111\u1ed3 b\u1ed1i c\u1ea3nh \u0111\u1ec3 hi\u1ec3u r\u00f5 ranh gi\u1edbi. X\u00e1c \u0111\u1ecbnh t\u1ea5t c\u1ea3 c\u00e1c \u0111\u1ea7u v\u00e0o v\u00e0 \u0111\u1ea7u ra.<\/li>\n
- Ph\u00e2n t\u00edch c\u00e1c qu\u00e1 tr\u00ecnh:<\/strong> Ph\u00e2n t\u00e1ch c\u00e1c qu\u00e1 tr\u00ecnh \u0111\u1ec3 hi\u1ec3u r\u00f5 c\u00e1c ph\u00e9p bi\u1ebfn \u0111\u1ed5i d\u1eef li\u1ec7u c\u1ee5 th\u1ec3 c\u1ea7n thi\u1ebft.<\/li>\n
- X\u00e1c \u0111\u1ecbnh c\u00e1c th\u1ef1c th\u1ec3 d\u1eef li\u1ec7u:<\/strong> Khi ph\u00e2n t\u00edch lu\u1ed3ng d\u1eef li\u1ec7u, h\u00e3y x\u00e1c \u0111\u1ecbnh c\u00e1c \u0111\u1ed1i t\u01b0\u1ee3ng b\u1ec1n v\u1eefng \u0111ang \u0111\u01b0\u1ee3c di chuy\u1ec3n. Nh\u1eefng \u0111\u1ed1i t\u01b0\u1ee3ng n\u00e0y tr\u1edf th\u00e0nh c\u00e1c th\u1ef1c th\u1ec3 ti\u1ec1m n\u0103ng cho s\u01a1 \u0111\u1ed3 ERD.<\/li>\n
- Thi\u1ebft k\u1ebf s\u01a1 \u0111\u1ed3 ERD:<\/strong> T\u1ea1o s\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3 \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh c\u00e1ch c\u00e1c th\u1ef1c th\u1ec3 n\u00e0y \u0111\u01b0\u1ee3c l\u01b0u tr\u1eef v\u00e0 li\u00ean k\u1ebft v\u1edbi nhau.<\/li>\n
- X\u00e1c minh lu\u1ed3ng d\u1eef li\u1ec7u:<\/strong> \u00c1nh x\u1ea1 l\u1ea1i c\u00e1c lu\u1ed3ng d\u1eef li\u1ec7u v\u1ec1 c\u00e1c b\u1ea3ng c\u01a1 s\u1edf d\u1eef li\u1ec7u. \u0110\u1ea3m b\u1ea3o m\u1ed7i qu\u00e1 tr\u00ecnh trong DFD \u0111\u1ec1u c\u00f3 thao t\u00e1c l\u01b0u tr\u1eef t\u01b0\u01a1ng \u1ee9ng trong ERD.<\/li>\n<\/ol>\n
\u00c1nh x\u1ea1 c\u00e1c kho d\u1eef li\u1ec7u<\/h3>\n
Trong DFD, m\u1ed9t kho d\u1eef li\u1ec7u l\u00e0 m\u1ed9t ch\u1ed7 tr\u1ed1ng chung chung. Trong ERD, kho d\u1eef li\u1ec7u \u0111\u00f3 tr\u1edf th\u00e0nh \u0111\u1ecbnh ngh\u0129a b\u1ea3ng chi ti\u1ebft. Quy tr\u00ecnh \u00e1nh x\u1ea1 bao g\u1ed3m:<\/p>\n
- \n
- Chuy\u1ec3n \u0111\u1ed5i c\u00e1c kho d\u1eef li\u1ec7u DFD th\u00e0nh c\u00e1c th\u1ef1c th\u1ec3 ERD.<\/li>\n
- \u0110\u1ea3m b\u1ea3o t\u1ea5t c\u1ea3 c\u00e1c thu\u1ed9c t\u00ednh trong lu\u1ed3ng DFD \u0111\u1ec1u \u0111\u01b0\u1ee3c t\u00ednh \u0111\u1ebfn trong c\u00e1c thu\u1ed9c t\u00ednh ERD.<\/li>\n
- Ki\u1ec3m tra xem b\u1ed9i s\u1ed1 trong ERD c\u00f3 h\u1ed7 tr\u1ee3 b\u1ed9i s\u1ed1 c\u1ee7a c\u00e1c lu\u1ed3ng trong DFD hay kh\u00f4ng.<\/li>\n<\/ul>\n
V\u00ed d\u1ee5, n\u1ebfu DFD hi\u1ec3n th\u1ecb m\u1ed9t \u201cKh\u00e1ch h\u00e0ng\u201d g\u1eedi nhi\u1ec1u \u201c\u0110\u01a1n h\u00e0ng\u201d, th\u00ec ERD ph\u1ea3i ph\u1ea3n \u00e1nh m\u1ed1i quan h\u1ec7 M\u1ed9t-\u0110a gi\u1eefa th\u1ef1c th\u1ec3 Kh\u00e1ch h\u00e0ng v\u00e0 \u0110\u01a1n h\u00e0ng. N\u1ebfu DFD ng\u1ee5 \u00fd m\u1ed9t m\u1ed1i quan h\u1ec7 nhi\u1ec1u-\u0111a ph\u1ee9c t\u1ea1p (v\u00ed d\u1ee5: \u201cSinh vi\u00ean\u201d v\u00e0 \u201cKh\u00f3a h\u1ecdc\u201d), th\u00ec ERD ph\u1ea3i gi\u1edbi thi\u1ec7u m\u1ed9t th\u1ef1c th\u1ec3 li\u00ean k\u1ebft \u0111\u1ec3 gi\u1ea3i quy\u1ebft n\u00f3.<\/p>\n
Nh\u1eefng sai l\u1ea7m ph\u1ed5 bi\u1ebfn c\u1ea7n tr\u00e1nh \u26a0\ufe0f<\/h2>\n
L\u1eabn l\u1ed9n gi\u1eefa c\u00e1c m\u00f4 h\u00ecnh n\u00e0y ho\u1eb7c s\u1eed d\u1ee5ng sai c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn n\u1ee3 k\u1ef9 thu\u1eadt nghi\u00eam tr\u1ecdng. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 nh\u1eefng l\u1ed7i ph\u1ed5 bi\u1ebfn c\u1ea7n l\u01b0u \u00fd.<\/p>\n
1. L\u1eabn l\u1ed9n gi\u1eefa logic v\u00e0 l\u01b0u tr\u1eef<\/h3>\n
Kh\u00f4ng n\u00ean bao g\u1ed3m logic x\u1eed l\u00fd trong s\u01a1 \u0111\u1ed3 ERD. S\u01a1 \u0111\u1ed3 ERD n\u00ean \u0111\u1ecbnh ngh\u0129a c\u1ea5u tr\u00fac, ch\u1ee9 kh\u00f4ng ph\u1ea3i h\u00e0nh vi. N\u1ebfu b\u1ea1n nh\u1eadn th\u1ea5y m\u00ecnh \u0111ang v\u1ebd c\u00e1c m\u0169i t\u00ean \u0111\u1ea1i di\u1ec7n cho ‘x\u1eed l\u00fd’ trong ERD, c\u00f3 kh\u1ea3 n\u0103ng b\u1ea1n \u0111ang m\u00f4 t\u1ea3 DFD thay v\u00ec ERD.<\/p>\n
2. M\u00f4 h\u00ecnh h\u00f3a qu\u00e1 m\u1ee9c DFD<\/h3>\n
S\u01a1 \u0111\u1ed3 lu\u1ed3ng d\u1eef li\u1ec7u (DFD) kh\u00f4ng n\u00ean l\u00e0 s\u01a1 \u0111\u1ed3 l\u01b0u \u0111\u1ed3 c\u1ee7a m\u00e3 ngu\u1ed3n. N\u00f3 kh\u00f4ng n\u00ean chi ti\u1ebft t\u1eebng nh\u00e1nh \u0111i\u1ec1u ki\u1ec7n hay quy tr\u00ecnh x\u1eed l\u00fd l\u1ed7i. H\u00e3y gi\u1eef DFD \u1edf m\u1ee9c \u0111\u1ed9 logic. N\u1ebfu b\u1ea1n chi ti\u1ebft t\u1eebng c\u00e2u l\u1ec7nh ‘if-else’, s\u01a1 \u0111\u1ed3 s\u1ebd tr\u1edf n\u00ean kh\u00f3 \u0111\u1ecdc v\u00e0 m\u1ea5t \u0111i gi\u00e1 tr\u1ecb t\u1ed5ng quan c\u1ea5p cao.<\/p>\n
3. B\u1ecf qua t\u00ednh cardinality trong ERD<\/h3>\n
V\u1ebd c\u00e1c \u0111\u01b0\u1eddng n\u1ed1i gi\u1eefa c\u00e1c th\u1ef1c th\u1ec3 m\u00e0 kh\u00f4ng x\u00e1c \u0111\u1ecbnh cardinality l\u00e0 m\u1ed9t sai l\u1ea7m ph\u1ed5 bi\u1ebfn. M\u1ed9t \u0111\u01b0\u1eddng n\u1ed1i \u0111\u01a1n l\u1ebb kh\u00f4ng cho b\u1ea1n bi\u1ebft m\u1ed9t kh\u00e1ch h\u00e0ng c\u00f3 th\u1ec3 c\u00f3 0 \u0111\u01a1n h\u00e0ng hay m\u1ed9t tri\u1ec7u \u0111\u01a1n. Lu\u00f4n x\u00e1c \u0111\u1ecbnh r\u00f5 1:1, 1:N ho\u1eb7c M:N \u0111\u1ec3 tr\u00e1nh hi\u1ec3u nh\u1ea7m.<\/p>\n
4. B\u1ecf qua thu\u1ed9c t\u00ednh d\u1eef li\u1ec7u<\/h3>\n
C\u1ea3 hai s\u01a1 \u0111\u1ed3 \u0111\u1ec1u b\u1ecb \u1ea3nh h\u01b0\u1edfng khi c\u00e1c thu\u1ed9c t\u00ednh d\u1eef li\u1ec7u m\u01a1 h\u1ed3. Trong DFD, c\u00e1c lu\u1ed3ng ph\u1ea3i \u0111\u01b0\u1ee3c \u0111\u1eb7t t\u00ean m\u00f4 t\u1ea3 r\u00f5 r\u00e0ng (v\u00ed d\u1ee5: \u201cTh\u00f4ng tin thanh to\u00e1n \u0111\u00e3 x\u00e1c th\u1ef1c\u201d thay v\u00ec \u201cD\u1eef li\u1ec7u\u201d). Trong ERD, c\u00e1c thu\u1ed9c t\u00ednh n\u00ean x\u00e1c \u0111\u1ecbnh ki\u1ec3u d\u1eef li\u1ec7u v\u00e0 r\u00e0ng bu\u1ed9c khi c\u00f3 th\u1ec3.<\/p>\n
5. T\u1ea1o ra c\u00e1c qu\u00e1 tr\u00ecnh m\u1ed3 c\u00f4i<\/h3>\n
Trong DFD, m\u1ed9t qu\u00e1 tr\u00ecnh kh\u00f4ng th\u1ec3 t\u1ed3n t\u1ea1i n\u1ebfu kh\u00f4ng c\u00f3 d\u1eef li\u1ec7u ch\u1ea3y v\u00e0o ho\u1eb7c ra kh\u1ecfi n\u00f3. \u0110\u1ea3m b\u1ea3o m\u1ed7i h\u1ed9p qu\u00e1 tr\u00ecnh c\u00f3 \u00edt nh\u1ea5t m\u1ed9t lu\u1ed3ng v\u00e0o v\u00e0 m\u1ed9t lu\u1ed3ng ra. C\u00e1c qu\u00e1 tr\u00ecnh m\u1ed3 c\u00f4i cho th\u1ea5y logic ch\u1ebft ho\u1eb7c y\u00eau c\u1ea7u d\u1eef li\u1ec7u b\u1ecb thi\u1ebfu.<\/p>\n
C\u00e1c th\u1ef1c h\u00e0nh t\u1ed1t nh\u1ea5t cho t\u00e0i li\u1ec7u \ud83d\udcdd<\/h2>\n
\u0110\u1ec3 duy tr\u00ec s\u1ef1 r\u00f5 r\u00e0ng v\u00e0 h\u1eefu \u00edch, tu\u00e2n th\u1ee7 c\u00e1c ti\u00eau chu\u1ea9n t\u00e0i li\u1ec7u sau.<\/p>\n
- \n
- T\u00ean g\u1ecdi nh\u1ea5t qu\u00e1n:<\/strong>S\u1eed d\u1ee5ng c\u00f9ng m\u1ed9t thu\u1eadt ng\u1eef trong c\u1ea3 hai s\u01a1 \u0111\u1ed3. N\u1ebfu DFD g\u1ecdi n\u00f3 l\u00e0 \u201cKh\u00e1ch h\u00e0ng\u201d, th\u00ec ERD c\u0169ng n\u00ean g\u1ecdi l\u00e0 \u201cKh\u00e1ch h\u00e0ng\u201d, ch\u1ee9 kh\u00f4ng ph\u1ea3i \u201cNg\u01b0\u1eddi d\u00f9ng\u201d. T\u00ednh nh\u1ea5t qu\u00e1n gi\u00fap gi\u1ea3m t\u1ea3i nh\u1eadn th\u1ee9c cho \u0111\u1ed9i ng\u0169.<\/li>\n
- Ki\u1ec3m so\u00e1t phi\u00ean b\u1ea3n:<\/strong>Xem s\u01a1 \u0111\u1ed3 nh\u01b0 m\u00e3 ngu\u1ed3n. Duy tr\u00ec l\u1ecbch s\u1eed phi\u00ean b\u1ea3n. Khi h\u1ec7 th\u1ed1ng ph\u00e1t tri\u1ec3n, c\u00e1c s\u01a1 \u0111\u1ed3 ph\u1ea3i \u0111\u01b0\u1ee3c c\u1eadp nh\u1eadt \u0111\u1ec3 ph\u1ea3n \u00e1nh tr\u1ea1ng th\u00e1i hi\u1ec7n t\u1ea1i.<\/li>\n
- Ghi ch\u00fa b\u1ed1i c\u1ea3nh:<\/strong>Th\u00eam ch\u00fa th\u00edch v\u00e0o c\u00e1c khu v\u1ef1c ph\u1ee9c t\u1ea1p. N\u1ebfu m\u1ed9t m\u1ed1i quan h\u1ec7 kh\u00f4ng chu\u1ea9n, h\u00e3y gi\u1ea3i th\u00edch l\u00fd do. N\u1ebfu m\u1ed9t lu\u1ed3ng d\u1eef li\u1ec7u \u0111\u1ea1i di\u1ec7n cho m\u1ed9t c\u00f4ng vi\u1ec7c n\u1ec1n, h\u00e3y ghi ch\u00fa r\u1eb1ng n\u00f3 l\u00e0 b\u1ea5t \u0111\u1ed3ng b\u1ed9.<\/li>\n
- V\u00f2ng ki\u1ec3m tra:<\/strong>Th\u1ef1c hi\u1ec7n c\u00e1c cu\u1ed9c ki\u1ec3m tra ch\u00ednh th\u1ee9c v\u1edbi c\u1ea3 c\u00e1c b\u00ean li\u00ean quan v\u1ec1 kinh doanh (\u0111\u1ed1i v\u1edbi DFD) v\u00e0 c\u00e1c tr\u01b0\u1edfng nh\u00f3m k\u1ef9 thu\u1eadt (\u0111\u1ed1i v\u1edbi ERD). M\u1ed9t chuy\u00ean vi\u00ean ph\u00e2n t\u00edch kinh doanh c\u00f3 th\u1ec3 ph\u00e1t hi\u1ec7n l\u1ed7i logic trong DFD m\u00e0 m\u1ed9t l\u1eadp tr\u00ecnh vi\u00ean c\u00f3 th\u1ec3 b\u1ecf s\u00f3t, v\u00e0 ng\u01b0\u1ee3c l\u1ea1i.<\/li>\n<\/ul>\n
Suy ngh\u0129 cu\u1ed1i c\u00f9ng v\u1ec1 vi\u1ec7c l\u1ef1a ch\u1ecdn m\u00f4 h\u00ecnh \ud83e\udde0<\/h2>\n
Vi\u1ec7c l\u1ef1a ch\u1ecdn gi\u1eefa s\u01a1 \u0111\u1ed3 lu\u1ed3ng d\u1eef li\u1ec7u v\u00e0 s\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3 kh\u00f4ng ph\u1ea3i l\u00e0 vi\u1ec7c ch\u1ecdn m\u1ed9t trong hai m\u00e0 l\u00e0 ch\u1ecdn c\u00f4ng c\u1ee5 ph\u00f9 h\u1ee3p cho giai \u0111o\u1ea1n c\u1ee5 th\u1ec3 trong v\u00f2ng \u0111\u1eddi thi\u1ebft k\u1ebf. DFD l\u00e0m s\u00e1ng t\u1ecf con \u0111\u01b0\u1eddng d\u1eef li\u1ec7u \u0111i qua, \u0111\u1ea3m b\u1ea3o h\u1ec7 th\u1ed1ng ho\u1ea1t \u0111\u1ed9ng nh\u01b0 mong mu\u1ed1n. ERD c\u1ee7ng c\u1ed1 d\u1eef li\u1ec7u \u0111\u00f3, \u0111\u1ea3m b\u1ea3o d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c l\u01b0u tr\u1eef m\u1ed9t c\u00e1ch \u0111\u00e1ng tin c\u1eady v\u00e0 hi\u1ec7u qu\u1ea3.<\/p>\n
B\u1eb1ng c\u00e1ch n\u1eafm v\u1eefng m\u1ee5c \u0111\u00edch ri\u00eang bi\u1ec7t c\u1ee7a hai m\u00f4 h\u00ecnh n\u00e0y, c\u00e1c ki\u1ebfn tr\u00fac s\u01b0 c\u00f3 th\u1ec3 x\u00e2y d\u1ef1ng h\u1ec7 th\u1ed1ng v\u1eeba h\u1ee3p l\u00fd v\u1ec1 m\u1eb7t logic v\u1eeba v\u1eefng ch\u1eafc v\u1ec1 c\u1ea5u tr\u00fac. M\u1ee5c ti\u00eau kh\u00f4ng ph\u1ea3i l\u00e0 t\u1ea1o ra m\u1ed9t s\u01a1 \u0111\u1ed3 ho\u00e0n h\u1ea3o, m\u00e0 l\u00e0 t\u1ea1o ra s\u1ef1 hi\u1ec3u bi\u1ebft r\u00f5 r\u00e0ng v\u1ec1 h\u1ec7 th\u1ed1ng. Khi \u0111\u1ed9i ng\u0169 c\u00f3 th\u1ec3 nh\u00ecn v\u00e0o DFD v\u00e0 th\u1ea5y quy tr\u00ecnh, v\u00e0 nh\u00ecn v\u00e0o ERD v\u00e0 th\u1ea5y d\u1eef li\u1ec7u, n\u1ec1n t\u1ea3ng cho m\u1ed9t d\u1ef1 \u00e1n th\u00e0nh c\u00f4ng \u0111\u00e3 \u0111\u01b0\u1ee3c \u0111\u1eb7t v\u1eefng ch\u1eafc.<\/p>\n
H\u00e3y nh\u1edb r\u1eb1ng c\u00e1c m\u00f4 h\u00ecnh n\u00e0y l\u00e0 c\u00f4ng c\u1ee5 giao ti\u1ebfp. Gi\u00e1 tr\u1ecb c\u1ee7a ch\u00fang n\u1eb1m \u1edf s\u1ef1 hi\u1ec3u bi\u1ebft chung m\u00e0 ch\u00fang t\u1ea1o ra gi\u1eefa c\u00e1c th\u00e0nh vi\u00ean trong \u0111\u1ed9i. D\u00f9 b\u1ea1n \u0111ang v\u1ebd m\u1ed9t giao d\u1ecbch ph\u1ee9c t\u1ea1p hay \u0111\u1ecbnh ngh\u0129a h\u1ed3 s\u01a1 ng\u01b0\u1eddi d\u00f9ng, h\u00e3y lu\u00f4n t\u1eadp trung v\u00e0o s\u1ef1 r\u00f5 r\u00e0ng, \u0111\u1ed9 ch\u00ednh x\u00e1c v\u00e0 s\u1ef1 ph\u00f9 h\u1ee3p v\u1edbi m\u1ee5c ti\u00eau kinh doanh. V\u1edbi s\u1ef1 k\u1ebft h\u1ee3p \u0111\u00fang \u0111\u1eafn gi\u1eefa lu\u1ed3ng v\u00e0 c\u1ea5u tr\u00fac, thi\u1ebft k\u1ebf h\u1ec7 th\u1ed1ng tr\u1edf th\u00e0nh m\u1ed9t ngh\u1ec7 thu\u1eadt c\u00f3 k\u1ef7 lu\u1eadt thay v\u00ec m\u1ed9t tr\u00f2 ch\u01a1i suy \u0111o\u00e1n.<\/p>\n","protected":false},"excerpt":{"rendered":"
Thi\u1ebft k\u1ebf m\u1ed9t h\u1ec7 th\u1ed1ng ph\u1ea7n m\u1ec1m ph\u1ee9c t\u1ea1p \u0111\u00f2i h\u1ecfi b\u1ea3n \u0111\u1ed3 r\u00f5 r\u00e0ng v\u1ec1 c\u00e1ch d\u1eef li\u1ec7u di chuy\u1ec3n v\u00e0 n\u01a1i n\u00f3 \u0111\u01b0\u1ee3c l\u01b0u tr\u1eef. Kh\u00f4ng c\u00f3 c\u00e1ch ti\u1ebfp c\u1eadn c\u00f3 c\u1ea5u tr\u00fac, c\u00e1c ki\u1ebfn tr\u00fac c\u00f3 th\u1ec3 tr\u1edf n\u00ean mong manh, kh\u00f3 b\u1ea3o tr\u00ec v\u00e0 d\u1ec5 m\u1eafc l\u1ed7i logic. Hai k\u1ef9 thu\u1eadt m\u00f4 h\u00ecnh h\u00f3a n\u1ec1n t\u1ea3ng nh\u1ea5t trong k\u1ef9 thu\u1eadt h\u1ec7 th\u1ed1ng l\u00e0 S\u01a1 \u0111\u1ed3 D\u00f2ng D\u1eef li\u1ec7u (DFD) v\u00e0 S\u01a1 \u0111\u1ed3 Quan h\u1ec7 Th\u1ef1c th\u1ec3 (ERD). M\u1eb7c d\u00f9 c\u1ea3 hai \u0111\u1ec1u ph\u1ee5c v\u1ee5 ch\u1ee9c n\u0103ng quan tr\u1ecdng l\u00e0 tr\u1ef1c quan h\u00f3a, nh\u01b0ng ch\u00fang l\u1ea1i gi\u1ea3i quy\u1ebft nh\u1eefng kh\u00eda c\u1ea1nh c\u0103n b\u1ea3n kh\u00e1c nhau c\u1ee7a h\u1ec7 th\u1ed1ng. Hi\u1ec3u r\u00f5 s\u1ef1 kh\u00e1c bi\u1ec7t gi\u1eefa hai m\u00f4 h\u00ecnh n\u00e0y kh\u00f4ng ch\u1ec9 l\u00e0 m\u1ed9t b\u00e0i t\u1eadp h\u1ecdc thu\u1eadt; \u0111\u00f3 l\u00e0 nhu c\u1ea7u th\u1ef1c ti\u1ec5n \u0111\u1ed1i v\u1edbi c\u00e1c ki\u1ebfn tr\u00fac s\u01b0 h\u1ec7 th\u1ed1ng, chuy\u00ean vi\u00ean ph\u00e2n t\u00edch kinh doanh v\u00e0 nh\u00e0 ph\u00e1t tri\u1ec3n. Vi\u1ec7c s\u1eed d\u1ee5ng sai m\u00f4 h\u00ecnh \u1edf giai \u0111o\u1ea1n ph\u00e1t tri\u1ec3n kh\u00f4ng ph\u00f9 h\u1ee3p c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn hi\u1ec3u l\u1ea7m, hi\u1ec7u su\u1ea5t c\u01a1 s\u1edf d\u1eef li\u1ec7u k\u00e9m ho\u1eb7c logic kinh doanh b\u1ecb h\u1ecfng. H\u01b0\u1edbng d\u1eabn n\u00e0y kh\u00e1m ph\u00e1 nh\u1eefng n\u00e9t tinh t\u1ebf c\u1ee7a t\u1eebng lo\u1ea1i s\u01a1 \u0111\u1ed3, c\u00e1c th\u00e0nh ph\u1ea7n c\u1ee5 th\u1ec3 c\u1ee7a ch\u00fang, v\u00e0 c\u00e1c t\u00ecnh hu\u1ed1ng chi\u1ebfn l\u01b0\u1ee3c m\u00e0 m\u1ed9t m\u00f4 h\u00ecnh \u0111\u01b0\u1ee3c \u01b0u ti\u00ean h\u01a1n m\u00f4 h\u00ecnh kia. Hi\u1ec3u r\u00f5 S\u01a1 \u0111\u1ed3 D\u00f2ng D\u1eef li\u1ec7u (DFD) \ud83d\udd04 S\u01a1 \u0111\u1ed3 D\u00f2ng D\u1eef li\u1ec7u t\u1eadp trung v\u00e0o s\u1ef1 di chuy\u1ec3n c\u1ee7a d\u1eef li\u1ec7u qua m\u1ed9t h\u1ec7 th\u1ed1ng. N\u00f3 tr\u1ef1c quan h\u00f3a c\u00e1ch th\u00f4ng tin \u0111\u01b0\u1ee3c x\u1eed l\u00fd, chuy\u1ec3n \u0111\u1ed5i v\u00e0 l\u01b0u tr\u1eef. DFD kh\u00f4ng quan t\u00e2m \u0111\u1ebfn chi ti\u1ebft tri\u1ec3n khai v\u1eadt l\u00fd hay th\u1eddi gian th\u1ef1c hi\u1ec7n c\u00e1c qu\u00e1 tr\u00ecnh. Thay v\u00e0o \u0111\u00f3, n\u00f3 cung c\u1ea5p c\u00e1i nh\u00ecn c\u1ea5p cao v\u1ec1 lu\u1ed3ng logic c\u1ee7a th\u00f4ng tin. C\u00e1c th\u00e0nh ph\u1ea7n c\u1ed1t l\u00f5i c\u1ee7a DFD C\u00e1c th\u1ef1c th\u1ec3 b\u00ean ngo\u00e0i: Ch\u00fang \u0111\u1ea1i di\u1ec7n cho ngu\u1ed3n ho\u1eb7c \u0111\u00edch c\u1ee7a d\u1eef li\u1ec7u n\u1eb1m ngo\u00e0i ranh gi\u1edbi h\u1ec7 th\u1ed1ng. Ch\u00fang c\u00f3 th\u1ec3 l\u00e0 ng\u01b0\u1eddi d\u00f9ng, c\u00e1c h\u1ec7 th\u1ed1ng kh\u00e1c ho\u1eb7c t\u1ed5 ch\u1ee9c. Ch\u00fang kh\u1edfi t\u1ea1o ho\u1eb7c nh\u1eadn d\u1eef li\u1ec7u nh\u01b0ng kh\u00f4ng x\u1eed l\u00fd d\u1eef li\u1ec7u \u0111\u00f3 trong b\u1ed1i c\u1ea3nh m\u00f4 h\u00ecnh c\u1ee5 th\u1ec3 n\u00e0y. C\u00e1c qu\u00e1 tr\u00ecnh: \u0110\u01b0\u1ee3c bi\u1ec3u di\u1ec5n b\u1eb1ng c\u00e1c h\u00ecnh ch\u1eef nh\u1eadt tr\u00f2n, \u0111\u00e2y l\u00e0 c\u00e1c ho\u1ea1t \u0111\u1ed9ng bi\u1ebfn \u0111\u1ed5i d\u1eef li\u1ec7u \u0111\u1ea7u v\u00e0o th\u00e0nh d\u1eef li\u1ec7u \u0111\u1ea7u ra. M\u1ed9t qu\u00e1 tr\u00ecnh thay \u0111\u1ed5i tr\u1ea1ng th\u00e1i ho\u1eb7c d\u1ea1ng th\u1ee9c c\u1ee7a th\u00f4ng tin \u0111i qua n\u00f3. R\u1ea5t quan tr\u1ecdng l\u00e0 m\u1ed7i qu\u00e1 tr\u00ecnh ph\u1ea3i c\u00f3 \u00edt nh\u1ea5t m\u1ed9t \u0111\u1ea7u v\u00e0o v\u00e0 m\u1ed9t \u0111\u1ea7u ra. C\u00e1c kho d\u1eef li\u1ec7u: \u0110\u00e2y l\u00e0 c\u00e1c kho l\u01b0u tr\u1eef n\u01a1i d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c gi\u1eef \u0111\u1ec3 s\u1eed d\u1ee5ng sau n\u00e0y. Trong DFD, ch\u00fang \u0111\u1ea1i di\u1ec7n cho c\u00e1c t\u1ec7p tin, c\u01a1 s\u1edf d\u1eef li\u1ec7u ho\u1eb7c l\u01b0u tr\u1eef. Ch\u00fang kh\u00f4ng ng\u1ee5 \u00fd m\u1ed9t c\u00f4ng ngh\u1ec7 c\u1ee5 th\u1ec3 m\u00e0 ch\u1ec9 \u0111\u01a1n thu\u1ea7n l\u00e0 s\u1ef1 t\u1ed3n t\u1ea1i c\u1ee7a b\u1ed9 nh\u1edb b\u1ec1n v\u1eefng. C\u00e1c lu\u1ed3ng d\u1eef li\u1ec7u: \u0110\u01b0\u1ee3c bi\u1ec3u di\u1ec5n b\u1eb1ng c\u00e1c m\u0169i t\u00ean, ch\u00fang cho th\u1ea5y h\u01b0\u1edbng di chuy\u1ec3n c\u1ee7a d\u1eef li\u1ec7u. M\u1ed7i lu\u1ed3ng ph\u1ea3i \u0111\u01b0\u1ee3c ghi nh\u00e3n b\u1eb1ng t\u00ean c\u1ee7a g\u00f3i d\u1eef li\u1ec7u \u0111ang \u0111\u01b0\u1ee3c chuy\u1ec3n. C\u00e1c lu\u1ed3ng d\u1eef li\u1ec7u k\u1ebft n\u1ed1i c\u00e1c th\u1ef1c th\u1ec3, qu\u00e1 tr\u00ecnh v\u00e0 kho d\u1eef li\u1ec7u. C\u00e1c m\u1ee9c \u0111\u1ed9 tr\u1eebu t\u01b0\u1ee3ng DFD th\u01b0\u1eddng \u0111\u01b0\u1ee3c t\u1ea1o theo c\u00e1ch ph\u00e2n c\u1ea5p \u0111\u1ec3 qu\u1ea3n l\u00fd \u0111\u1ed9 ph\u1ee9c t\u1ea1p: S\u01a1 \u0111\u1ed3 b\u1ed1i c\u1ea3nh (M\u1ee9c 0): \u0110\u00e2y l\u00e0 c\u00e1i nh\u00ecn c\u1ea5p cao nh\u1ea5t. N\u00f3 th\u1ec3 hi\u1ec7n to\u00e0n b\u1ed9 h\u1ec7 th\u1ed1ng nh\u01b0 m\u1ed9t qu\u00e1 tr\u00ecnh duy nh\u1ea5t v\u00e0 x\u00e1c \u0111\u1ecbnh t\u1ea5t c\u1ea3 c\u00e1c th\u1ef1c th\u1ec3 b\u00ean ngo\u00e0i t\u01b0\u01a1ng t\u00e1c v\u1edbi n\u00f3. N\u00f3 x\u00e1c \u0111\u1ecbnh r\u00f5 ranh gi\u1edbi c\u1ee7a h\u1ec7 th\u1ed1ng. S\u01a1 \u0111\u1ed3 m\u1ee9c 1: \u0110\u00e2y l\u00e0 vi\u1ec7c chia nh\u1ecf qu\u00e1 tr\u00ecnh duy nh\u1ea5t t\u1eeb s\u01a1 \u0111\u1ed3 b\u1ed1i c\u1ea3nh th\u00e0nh c\u00e1c qu\u00e1 tr\u00ecnh con ch\u00ednh. N\u00f3 cung c\u1ea5p th\u00eam chi ti\u1ebft v\u1ec1 c\u00e1ch h\u1ec7 th\u1ed1ng x\u1eed l\u00fd d\u1eef li\u1ec7u b\u00ean trong m\u00e0 kh\u00f4ng b\u1ecb m\u1eafc k\u1eb9t v\u00e0o logic ph\u1ee9c t\u1ea1p. M\u1ee9c 2 v\u00e0 cao h\u01a1n: C\u00e1c s\u01a1 \u0111\u1ed3 n\u00e0y ph\u00e2n t\u00edch c\u1ee5 th\u1ec3 c\u00e1c qu\u00e1 tr\u00ecnh t\u1eeb m\u1ee9c 1 ra chi ti\u1ebft h\u01a1n. M\u1ee9c \u0111\u1ed9 n\u00e0y th\u01b0\u1eddng \u0111\u01b0\u1ee3c d\u00f9ng cho c\u00e1c module ph\u1ee9c t\u1ea1p, n\u01a1i c\u00e1c ph\u00e9p bi\u1ebfn \u0111\u1ed5i d\u1eef li\u1ec7u c\u1ee5 th\u1ec3 c\u1ea7n \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a ch\u1eb7t ch\u1ebd. Khi n\u00e0o n\u00ean \u00e1p d\u1ee5ng DFD DFD hi\u1ec7u qu\u1ea3 nh\u1ea5t trong giai \u0111o\u1ea1n thu th\u1eadp y\u00eau c\u1ea7u v\u00e0 thi\u1ebft k\u1ebf ch\u1ee9c n\u0103ng. Ch\u00fang gi\u00fap c\u00e1c b\u00ean li\u00ean quan h\u00ecnh dung h\u00e0nh vi c\u1ee7a h\u1ec7 th\u1ed1ng m\u00e0 kh\u00f4ng b\u1ecb ph\u00e2n t\u00e2m b\u1edfi c\u00e1c r\u00e0ng bu\u1ed9c k\u1ef9 thu\u1eadt. Ch\u00fang \u0111\u1eb7c bi\u1ec7t h\u1eefu \u00edch cho: Ph\u00e1t hi\u1ec7n c\u00e1c y\u00eau c\u1ea7u d\u1eef li\u1ec7u b\u1ecb thi\u1ebfu. Truy\u1ec1n \u0111\u1ea1t c\u00e1c quy tr\u00ecnh kinh doanh \u0111\u1ebfn c\u00e1c b\u00ean li\u00ean quan kh\u00f4ng chuy\u00ean v\u1ec1 k\u1ef9 thu\u1eadt. X\u00e1c \u0111\u1ecbnh ph\u1ea1m vi c\u1ee7a m\u1ed9t d\u1ef1 \u00e1n. Ph\u00e2n t\u00edch an ninh th\u00f4ng tin b\u1eb1ng c\u00e1ch x\u00e1c \u0111\u1ecbnh n\u01a1i d\u1eef li\u1ec7u nh\u1ea1y c\u1ea3m \u0111i v\u00e0o v\u00e0 r\u1eddi kh\u1ecfi h\u1ec7 th\u1ed1ng. Hi\u1ec3u r\u00f5 S\u01a1 \u0111\u1ed3 Quan h\u1ec7 Th\u1ef1c th\u1ec3 (ERD) \ud83d\udd17 Trong khi DFD theo d\u00f5i s\u1ef1 di chuy\u1ec3n, th\u00ec S\u01a1 \u0111\u1ed3 Quan h\u1ec7 Th\u1ef1c th\u1ec3 l\u1ea1i t\u1eadp trung v\u00e0o c\u1ea5u tr\u00fac. ERD l\u00e0 m\u1ed9t m\u00f4 h\u00ecnh kh\u00e1i ni\u1ec7m \u0111\u01b0\u1ee3c d\u00f9ng \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh y\u00eau c\u1ea7u d\u1eef li\u1ec7u v\u00e0 c\u00e1c m\u1ed1i quan h\u1ec7 b\u00ean trong c\u01a1 s\u1edf d\u1eef li\u1ec7u. N\u00f3 m\u00f4 t\u1ea3 b\u1ea3n ch\u1ea5t t\u0129nh c\u1ee7a d\u1eef li\u1ec7u, \u0111\u1ea3m b\u1ea3o t\u00ednh to\u00e0n v\u1eb9n v\u00e0 chu\u1ea9n h\u00f3a. C\u00e1c th\u00e0nh ph\u1ea7n ch\u00ednh c\u1ee7a s\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3 C\u00e1c th\u1ef1c th\u1ec3:\u0110\u01b0\u1ee3c bi\u1ec3u di\u1ec5n d\u01b0\u1edbi d\u1ea1ng h\u00ecnh ch\u1eef nh\u1eadt, \u0111\u00e2y l\u00e0 c\u00e1c \u0111\u1ed1i t\u01b0\u1ee3ng ho\u1eb7c kh\u00e1i ni\u1ec7m trong th\u1ebf gi\u1edbi th\u1ef1c m\u00e0 d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c l\u01b0u tr\u1eef. C\u00e1c v\u00ed d\u1ee5 bao g\u1ed3m \u201cKh\u00e1ch h\u00e0ng,\u201d \u201c\u0110\u01a1n h\u00e0ng,\u201d ho\u1eb7c \u201cS\u1ea3n ph\u1ea9m.\u201d C\u00e1c th\u1ef1c th\u1ec3 l\u00e0 c\u00e1c kh\u1ed1i x\u00e2y d\u1ef1ng ch\u00ednh c\u1ee7a c\u1ea5u tr\u00fac d\u1eef li\u1ec7u. Thu\u1ed9c t\u00ednh:\u0110\u00e2y l\u00e0 c\u00e1c thu\u1ed9c t\u00ednh ho\u1eb7c \u0111\u1eb7c \u0111i\u1ec3m c\u1ee7a m\u1ed9t th\u1ef1c th\u1ec3. Ch\u00fang th\u01b0\u1eddng \u0111\u01b0\u1ee3c li\u1ec7t k\u00ea b\u00ean trong h\u1ed9p th\u1ef1c th\u1ec3 ho\u1eb7c k\u1ebft n\u1ed1i v\u1edbi n\u00f3. C\u00e1c thu\u1ed9c t\u00ednh x\u00e1c \u0111\u1ecbnh c\u00e1c \u0111i\u1ec3m d\u1eef li\u1ec7u c\u1ee5 th\u1ec3, ch\u1eb3ng h\u1ea1n nh\u01b0 \u201cM\u00e3 kh\u00e1ch h\u00e0ng\u201d ho\u1eb7c \u201cNg\u00e0y \u0111\u1eb7t h\u00e0ng.\u201d M\u1ed9t s\u1ed1<\/p>\n","protected":false},"author":1,"featured_media":4239,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_yoast_wpseo_title":"DFD so v\u1edbi ERD: Khi n\u00e0o n\u00ean s\u1eed d\u1ee5ng t\u1eebng lo\u1ea1i trong thi\u1ebft k\u1ebf h\u1ec7 th\u1ed1ng","_yoast_wpseo_metadesc":"M\u1ed9t h\u01b0\u1edbng d\u1eabn to\u00e0n di\u1ec7n so s\u00e1nh s\u01a1 \u0111\u1ed3 lu\u1ed3ng d\u1eef li\u1ec7u v\u00e0 s\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3. H\u1ecdc c\u00e1ch khi n\u00e0o n\u00ean s\u1eed d\u1ee5ng DFD hay ERD \u0111\u1ec3 \u0111\u1ea1t \u0111\u01b0\u1ee3c ki\u1ebfn tr\u00fac h\u1ec7 th\u1ed1ng t\u1ed1i \u01b0u.","fifu_image_url":"","fifu_image_alt":"","footnotes":""},"categories":[84],"tags":[77,83],"class_list":["post-4238","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-dfd","tag-academic","tag-dfd"],"yoast_head":"\n
DFD so v\u1edbi ERD: Khi n\u00e0o n\u00ean s\u1eed d\u1ee5ng t\u1eebng lo\u1ea1i trong thi\u1ebft k\u1ebf h\u1ec7 th\u1ed1ng<\/title>\n<meta name=\"description\" content=\"M\u1ed9t h\u01b0\u1edbng d\u1eabn to\u00e0n di\u1ec7n so s\u00e1nh s\u01a1 \u0111\u1ed3 lu\u1ed3ng d\u1eef li\u1ec7u v\u00e0 s\u01a1 \u0111\u1ed3 quan h\u1ec7 th\u1ef1c th\u1ec3. 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H\u1ecdc c\u00e1ch khi n\u00e0o n\u00ean s\u1eed d\u1ee5ng DFD hay ERD \u0111\u1ec3 \u0111\u1ea1t \u0111\u01b0\u1ee3c ki\u1ebfn tr\u00fac h\u1ec7 th\u1ed1ng t\u1ed1i \u01b0u.","breadcrumb":{"@id":"https:\/\/www.diagrams-ai.com\/vn\/dfd-vs-erd-system-design-guide\/#breadcrumb"},"inLanguage":"vi","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.diagrams-ai.com\/vn\/dfd-vs-erd-system-design-guide\/"]}]},{"@type":"ImageObject","inLanguage":"vi","@id":"https:\/\/www.diagrams-ai.com\/vn\/dfd-vs-erd-system-design-guide\/#primaryimage","url":"https:\/\/www.diagrams-ai.com\/vn\/wp-content\/uploads\/sites\/10\/2026\/03\/dfd-vs-erd-system-design-infographic-chalkboard-style.jpg","contentUrl":"https:\/\/www.diagrams-ai.com\/vn\/wp-content\/uploads\/sites\/10\/2026\/03\/dfd-vs-erd-system-design-infographic-chalkboard-style.jpg","width":1664,"height":928},{"@type":"BreadcrumbList","@id":"https:\/\/www.diagrams-ai.com\/vn\/dfd-vs-erd-system-design-guide\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.diagrams-ai.com\/vn\/"},{"@type":"ListItem","position":2,"name":"DFD so v\u1edbi ERD: Khi n\u00e0o n\u00ean s\u1eed d\u1ee5ng t\u1eebng lo\u1ea1i trong thi\u1ebft k\u1ebf h\u1ec7 th\u1ed1ng"}]},{"@type":"WebSite","@id":"https:\/\/www.diagrams-ai.com\/vn\/#website","url":"https:\/\/www.diagrams-ai.com\/vn\/","name":"Diagrams AI Vietnamese","description":"","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.diagrams-ai.com\/vn\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"vi"},{"@type":"Person","@id":"https:\/\/www.diagrams-ai.com\/vn\/#\/schema\/person\/ecc36153eaeb4aeaf895589c93d5de12","name":"vpadmin","image":{"@type":"ImageObject","inLanguage":"vi","@id":"https:\/\/www.diagrams-ai.com\/vn\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/56e0eb902506d9cea7c7e209205383146b8e81c0ef2eff693d9d5e0276b3d7e3?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/56e0eb902506d9cea7c7e209205383146b8e81c0ef2eff693d9d5e0276b3d7e3?s=96&d=mm&r=g","caption":"vpadmin"},"sameAs":["https:\/\/www.diagrams-ai.com"],"url":"https:\/\/www.diagrams-ai.com\/vn\/author\/vpadmin\/"}]}},"_links":{"self":[{"href":"https:\/\/www.diagrams-ai.com\/vn\/wp-json\/wp\/v2\/posts\/4238","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.diagrams-ai.com\/vn\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.diagrams-ai.com\/vn\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.diagrams-ai.com\/vn\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.diagrams-ai.com\/vn\/wp-json\/wp\/v2\/comments?post=4238"}],"version-history":[{"count":0,"href":"https:\/\/www.diagrams-ai.com\/vn\/wp-json\/wp\/v2\/posts\/4238\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.diagrams-ai.com\/vn\/wp-json\/wp\/v2\/media\/4239"}],"wp:attachment":[{"href":"https:\/\/www.diagrams-ai.com\/vn\/wp-json\/wp\/v2\/media?parent=4238"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.diagrams-ai.com\/vn\/wp-json\/wp\/v2\/categories?post=4238"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.diagrams-ai.com\/vn\/wp-json\/wp\/v2\/tags?post=4238"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}} - Ki\u1ec3m so\u00e1t phi\u00ean b\u1ea3n:<\/strong>Xem s\u01a1 \u0111\u1ed3 nh\u01b0 m\u00e3 ngu\u1ed3n. Duy tr\u00ec l\u1ecbch s\u1eed phi\u00ean b\u1ea3n. Khi h\u1ec7 th\u1ed1ng ph\u00e1t tri\u1ec3n, c\u00e1c s\u01a1 \u0111\u1ed3 ph\u1ea3i \u0111\u01b0\u1ee3c c\u1eadp nh\u1eadt \u0111\u1ec3 ph\u1ea3n \u00e1nh tr\u1ea1ng th\u00e1i hi\u1ec7n t\u1ea1i.<\/li>\n
- T\u00ean g\u1ecdi nh\u1ea5t qu\u00e1n:<\/strong>S\u1eed d\u1ee5ng c\u00f9ng m\u1ed9t thu\u1eadt ng\u1eef trong c\u1ea3 hai s\u01a1 \u0111\u1ed3. N\u1ebfu DFD g\u1ecdi n\u00f3 l\u00e0 \u201cKh\u00e1ch h\u00e0ng\u201d, th\u00ec ERD c\u0169ng n\u00ean g\u1ecdi l\u00e0 \u201cKh\u00e1ch h\u00e0ng\u201d, ch\u1ee9 kh\u00f4ng ph\u1ea3i \u201cNg\u01b0\u1eddi d\u00f9ng\u201d. T\u00ednh nh\u1ea5t qu\u00e1n gi\u00fap gi\u1ea3m t\u1ea3i nh\u1eadn th\u1ee9c cho \u0111\u1ed9i ng\u0169.<\/li>\n
- Ph\u00e2n t\u00edch c\u00e1c qu\u00e1 tr\u00ecnh:<\/strong> Ph\u00e2n t\u00e1ch c\u00e1c qu\u00e1 tr\u00ecnh \u0111\u1ec3 hi\u1ec3u r\u00f5 c\u00e1c ph\u00e9p bi\u1ebfn \u0111\u1ed5i d\u1eef li\u1ec7u c\u1ee5 th\u1ec3 c\u1ea7n thi\u1ebft.<\/li>\n
- Di d\u1eddi h\u1ec7 th\u1ed1ng c\u0169:<\/strong> Khi di chuy\u1ec3n d\u1eef li\u1ec7u t\u1eeb h\u1ec7 th\u1ed1ng c\u0169 sang h\u1ec7 th\u1ed1ng m\u1edbi, vi\u1ec7c hi\u1ec3u r\u00f5 c\u00e1c m\u1ed1i quan h\u1ec7 hi\u1ec7n c\u00f3 l\u00e0 then ch\u1ed1t. S\u01a1 \u0111\u1ed3 ERD gi\u00fap \u00e1nh x\u1ea1 c\u00e1c b\u1ea3ng c\u0169 sang c\u1ea5u tr\u00fac m\u1edbi, \u0111\u1ea3m b\u1ea3o kh\u00f4ng c\u00f3 d\u1eef li\u1ec7u n\u00e0o b\u1ecb m\u1ea5t ho\u1eb7c h\u1ecfng.<\/li>\n
- T\u00edch h\u1ee3p b\u00ean ngo\u00e0i:<\/strong> Khi m\u1ed9t h\u1ec7 th\u1ed1ng t\u01b0\u01a1ng t\u00e1c v\u1edbi nhi\u1ec1u API b\u00ean ngo\u00e0i ho\u1eb7c c\u00e1c h\u1ec7 th\u1ed1ng c\u0169, s\u01a1 \u0111\u1ed3 lu\u1ed3ng d\u1eef li\u1ec7u (DFD) gi\u00fap x\u00e1c \u0111\u1ecbnh c\u00e1c \u0111i\u1ec3m v\u00e0o v\u00e0 ra c\u1ee7a d\u1eef li\u1ec7u. N\u00f3 ng\u0103n ng\u1eeba m\u1ea5t d\u1eef li\u1ec7u trong qu\u00e1 tr\u00ecnh chuy\u1ec3n giao gi\u1eefa c\u00e1c h\u1ec7 th\u1ed1ng.<\/li>\n
- T\u1ef1 \u0111\u1ed9ng h\u00f3a quy tr\u00ecnh l\u00e0m vi\u1ec7c:<\/strong> N\u1ebfu h\u1ec7 th\u1ed1ng li\u00ean quan \u0111\u1ebfn c\u00e1c chu\u1ed7i ph\u00ea duy\u1ec7t ph\u1ee9c t\u1ea1p, thay \u0111\u1ed5i tr\u1ea1ng th\u00e1i ho\u1eb7c giao d\u1ecbch nhi\u1ec1u b\u01b0\u1edbc, s\u01a1 \u0111\u1ed3 lu\u1ed3ng d\u1eef li\u1ec7u (DFD) s\u1ebd l\u00e0m r\u00f5 tr\u00ecnh t\u1ef1 c\u00e1c thao t\u00e1c. N\u00f3 gi\u00fap x\u00e1c \u0111\u1ecbnh c\u00e1c \u0111i\u1ec3m ngh\u1ebdn trong quy tr\u00ecnh.<\/li>\n
- Thu\u1ed9c t\u00ednh:<\/strong>\u0110\u00e2y l\u00e0 c\u00e1c thu\u1ed9c t\u00ednh ho\u1eb7c \u0111\u1eb7c \u0111i\u1ec3m c\u1ee7a m\u1ed9t th\u1ef1c th\u1ec3. Ch\u00fang th\u01b0\u1eddng \u0111\u01b0\u1ee3c li\u1ec7t k\u00ea b\u00ean trong h\u1ed9p th\u1ef1c th\u1ec3 ho\u1eb7c k\u1ebft n\u1ed1i v\u1edbi n\u00f3. C\u00e1c thu\u1ed9c t\u00ednh x\u00e1c \u0111\u1ecbnh c\u00e1c \u0111i\u1ec3m d\u1eef li\u1ec7u c\u1ee5 th\u1ec3, ch\u1eb3ng h\u1ea1n nh\u01b0 \u201cM\u00e3 kh\u00e1ch h\u00e0ng\u201d ho\u1eb7c \u201cNg\u00e0y \u0111\u1eb7t h\u00e0ng.\u201d M\u1ed9t s\u1ed1 thu\u1ed9c t\u00ednh \u0111\u00f3ng vai tr\u00f2 l\u00e0 kh\u00f3a ch\u00ednh, x\u00e1c \u0111\u1ecbnh duy nh\u1ea5t m\u1ed9t b\u1ea3n ghi.<\/li>\n
- C\u00e1c th\u1ef1c th\u1ec3:<\/strong>\u0110\u01b0\u1ee3c bi\u1ec3u di\u1ec5n d\u01b0\u1edbi d\u1ea1ng h\u00ecnh ch\u1eef nh\u1eadt, \u0111\u00e2y l\u00e0 c\u00e1c \u0111\u1ed1i t\u01b0\u1ee3ng ho\u1eb7c kh\u00e1i ni\u1ec7m trong th\u1ebf gi\u1edbi th\u1ef1c m\u00e0 d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c l\u01b0u tr\u1eef. C\u00e1c v\u00ed d\u1ee5 bao g\u1ed3m \u201cKh\u00e1ch h\u00e0ng,\u201d \u201c\u0110\u01a1n h\u00e0ng,\u201d ho\u1eb7c \u201cS\u1ea3n ph\u1ea9m.\u201d C\u00e1c th\u1ef1c th\u1ec3 l\u00e0 c\u00e1c kh\u1ed1i x\u00e2y d\u1ef1ng ch\u00ednh c\u1ee7a c\u1ea5u tr\u00fac d\u1eef li\u1ec7u.<\/li>\n
- S\u01a1 \u0111\u1ed3 m\u1ee9c 1:<\/strong> \u0110\u00e2y l\u00e0 vi\u1ec7c chia nh\u1ecf qu\u00e1 tr\u00ecnh duy nh\u1ea5t t\u1eeb s\u01a1 \u0111\u1ed3 b\u1ed1i c\u1ea3nh th\u00e0nh c\u00e1c qu\u00e1 tr\u00ecnh con ch\u00ednh. N\u00f3 cung c\u1ea5p th\u00eam chi ti\u1ebft v\u1ec1 c\u00e1ch h\u1ec7 th\u1ed1ng x\u1eed l\u00fd d\u1eef li\u1ec7u b\u00ean trong m\u00e0 kh\u00f4ng b\u1ecb m\u1eafc k\u1eb9t v\u00e0o logic ph\u1ee9c t\u1ea1p.<\/li>\n