{"id":9088,"date":"2025-03-25T16:50:59","date_gmt":"2025-03-25T09:50:59","guid":{"rendered":"https:\/\/mb668s.com\/cam-nang-7mb66-xoc-dia\/?p=9088"},"modified":"2025-03-25T16:51:01","modified_gmt":"2025-03-25T09:51:01","slug":"database-schema-la-gi","status":"publish","type":"post","link":"https:\/\/mb668s.com\/cam-nang-7mb66-xoc-dia\/tu-van-nghe-nghiep\/database-schema-la-gi","title":{"rendered":"Database schema l\u00e0 g\u00ec? Kh\u00e1m ph\u00e1 t\u1ea7m quan tr\u1ecdng trong qu\u1ea3n l\u00fd d\u1eef li\u1ec7u"},"content":{"rendered":"\n

Database schema l\u00e0 g\u00ec?<\/strong> \u0110\u00e2y l\u00e0 m\u1ed9t c\u00e2u h\u1ecfi quan tr\u1ecdng trong l\u0129nh v\u1ef1c qu\u1ea3n l\u00fd d\u1eef li\u1ec7u v\u00e0 h\u1ec7 th\u1ed1ng th\u00f4ng tin. Khi b\u1ea1n h\u1ecdc v\u1ec1 c\u01a1 s\u1edf d\u1eef li\u1ec7u, vi\u1ec7c n\u1eafm r\u00f5 kh\u00e1i ni\u1ec7m n\u00e0y s\u1ebd gi\u00fap b\u1ea1n thi\u1ebft k\u1ebf v\u00e0 t\u1ed1i \u01b0u h\u00f3a c\u1ea5u tr\u00fac d\u1eef li\u1ec7u m\u1ed9t c\u00e1ch hi\u1ec7u qu\u1ea3 h\u01a1n. Trong b\u00e0i vi\u1ebft n\u00e0y, ch\u00fang ta s\u1ebd c\u00f9ng nhau kh\u00e1m ph\u00e1 chi ti\u1ebft v\u1ec1 database schema, t\u1eeb \u0111\u1ecbnh ngh\u0129a \u0111\u1ebfn l\u1ee3i \u00edch, c\u00e1ch t\u1ea1o ra v\u00e0 nh\u1eefng \u0111i\u1ec1u c\u1ea7n l\u01b0u \u00fd khi thi\u1ebft k\u1ebf n\u00f3.<\/p>\n\n\n

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\"Database-schema-la-gi.png\"<\/figure>\n<\/div>\n\n\n

Database schema (L\u01b0\u1ee3c \u0111\u1ed3 CSDL) l\u00e0 g\u00ec?<\/strong><\/h2>\n\n\n\n
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\u0110\u1ec3 hi\u1ec3u r\u00f5 h\u01a1n v\u1ec1 kh\u00e1i ni\u1ec7m database schema<\/strong>, tr\u01b0\u1edbc ti\u00ean ch\u00fang ta c\u1ea7n x\u00e1c \u0111\u1ecbnh m\u1ed9t s\u1ed1 thu\u1eadt ng\u1eef li\u00ean quan. L\u01b0\u1ee3c \u0111\u1ed3 c\u01a1 s\u1edf d\u1eef li\u1ec7u l\u00e0 m\u1ed9t m\u00f4 t\u1ea3 t\u1ed5ng qu\u00e1t v\u1ec1 c\u1ea5u tr\u00fac c\u1ee7a c\u01a1 s\u1edf d\u1eef li\u1ec7u, bao g\u1ed3m c\u00e1c b\u1ea3ng, m\u1ed1i quan h\u1ec7 gi\u1eefa c\u00e1c b\u1ea3ng, ki\u1ec3u d\u1eef li\u1ec7u v\u00e0 c\u00e1c r\u00e0ng bu\u1ed9c kh\u00e1c. N\u00f3 \u0111\u00f3ng vai tr\u00f2 nh\u01b0 m\u1ed9t b\u1ea3n \u0111\u1ed3 h\u01b0\u1edbng d\u1eabn cho c\u00e1ch m\u00e0 d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c t\u1ed5 ch\u1ee9c v\u00e0 l\u01b0u tr\u1eef trong h\u1ec7 th\u1ed1ng.<\/p>\n<\/blockquote>\n\n\n\n

\u0110\u1ecbnh ngh\u0129a c\u01a1 b\u1ea3n<\/strong><\/h3>\n\n\n\n

Schema SQL l\u00e0 g\u00ec<\/strong>? Schema trong SQL th\u01b0\u1eddng \u0111\u01b0\u1ee3c hi\u1ec3u l\u00e0 m\u1ed9t t\u1eadp h\u1ee3p c\u00e1c \u0111\u1ed1i t\u01b0\u1ee3ng trong c\u01a1 s\u1edf d\u1eef li\u1ec7u nh\u01b0 b\u1ea3ng, ch\u1ec9 m\u1ee5c, quan h\u1ec7 v\u00e0 c\u00e1c quy t\u1eafc kh\u00e1c. N\u00f3 cho ph\u00e9p ng\u01b0\u1eddi d\u00f9ng t\u1ed5 ch\u1ee9c d\u1eef li\u1ec7u theo c\u00e1c c\u00e1ch th\u1ee9c kh\u00e1c nhau \u0111\u1ec3 d\u1ec5 d\u00e0ng qu\u1ea3n l\u00fd v\u00e0 truy v\u1ea5n.<\/p>\n\n\n\n

B\u1eb1ng c\u00e1ch s\u1eed d\u1ee5ng schema trong SQL<\/strong>, ng\u01b0\u1eddi ph\u00e1t tri\u1ec3n c\u00f3 th\u1ec3 \u0111\u1ecbnh ngh\u0129a c\u00e1c b\u1ea3ng v\u1edbi c\u00e1c ki\u1ec3u d\u1eef li\u1ec7u kh\u00e1c nhau v\u00e0 ch\u1ec9 \u0111\u1ecbnh c\u00e1c m\u1ed1i quan h\u1ec7 gi\u1eefa ch\u00fang. \u0110i\u1ec1u n\u00e0y kh\u00f4ng ch\u1ec9 gi\u00fap ng\u0103n ng\u1eeba s\u1ef1 tr\u00f9ng l\u1eb7p d\u1eef li\u1ec7u m\u00e0 c\u00f2n t\u1ed1i \u01b0u h\u00f3a kh\u1ea3 n\u0103ng truy xu\u1ea5t th\u00f4ng tin.<\/p>\n\n\n\n

C\u00e1c th\u00e0nh ph\u1ea7n ch\u00ednh c\u1ee7a database schema<\/strong><\/h3>\n\n\n\n

M\u1ed9t l\u01b0\u1ee3c \u0111\u1ed3 c\u01a1 s\u1edf d\u1eef li\u1ec7u c\u00f3 th\u1ec3 bao g\u1ed3m nhi\u1ec1u th\u00e0nh ph\u1ea7n kh\u00e1c nhau, ch\u1eb3ng h\u1ea1n nh\u01b0:<\/p>\n\n\n\n