{"id":313366,"date":"2024-01-31T16:11:31","date_gmt":"2024-01-31T09:11:31","guid":{"rendered":"https:\/\/hoanghamobile.com\/tin-tuc\/?p=313366"},"modified":"2024-01-31T16:11:31","modified_gmt":"2024-01-31T09:11:31","slug":"sql-join","status":"publish","type":"post","link":"https:\/\/hoanghamobile.com\/tin-tuc\/sql-join\/","title":{"rendered":"JOIN trong SQL Server"},"content":{"rendered":"

Nh\u1eefng ai mu\u1ed1n tr\u1edf th\u00e0nh l\u1eadp tr\u00ecnh vi\u00ean hay m\u1edbi ti\u1ebfp c\u1eadn l\u0129nh v\u1ef1c c\u00f4ng ngh\u1ec7 th\u00f4ng tin th\u00ec ch\u1eafc ch\u1eafn ph\u1ea3i t\u00ecm hi\u1ec3u SQL join l\u00e0 g\u00ec v\u00e0 c\u00e1ch d\u00f9ng c\u00e2u l\u1ec7nh n\u00e0y nh\u01b0 th\u1ebf n\u00e0o. B\u00e0i vi\u1ebft sau \u0111\u00e2y s\u1ebd chia s\u1ebb \u0111\u1ebfn b\u1ea1n nh\u1eefng th\u00f4ng tin v\u1ec1 Join trong SQL Server c\u00f9ng v\u1edbi c\u00e1c v\u00ed d\u1ee5 c\u1ee5 th\u1ec3 \u0111\u1ec3 b\u1ea1n hi\u1ec3u theo c\u00e1ch \u0111\u01a1n gi\u1ea3n h\u01a1n.<\/span><\/p>\n

SQL Server l\u00e0 g\u00ec?<\/span><\/h2>\n

\u0110\u00e2y l\u00e0 m\u1ed9t ph\u1ea7n m\u1ec1m do Microsoft ph\u00e1t tri\u1ec3n v\u00e0 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng v\u00e0o m\u1ee5c \u0111\u00edch l\u01b0u tr\u1eef, truy xu\u1ea5t c\u00e1c d\u1eef li\u1ec7u theo chu\u1ea9n RDBMS. M\u1ed7i RDBMS s\u1ebd bao g\u1ed3m c\u00f4ng c\u1ee5 CSDL (c\u01a1 s\u1edf d\u1eef li\u1ec7u), CSDL, nh\u1eefng \u1ee9ng d\u1ee5ng \u0111\u1ec3 qu\u1ea3n l\u00fd c\u00e1c d\u1eef li\u1ec7u c\u00f9ng nh\u1eefng b\u1ed9 ph\u1eadn li\u00ean quan,…<\/span><\/p>\n

\"sql-join-1\"<\/picture>
SQL Server l\u00e0 g\u00ec?<\/figcaption><\/figure>\n

Phi\u00ean b\u1ea3n SQL Server \u0111\u1ea7u ti\u00ean m\u00e0 Microsoft ph\u00e1t h\u00e0nh l\u00e0 v\u00e0o n\u0103m 1989. Phi\u00ean b\u1ea3n n\u00e0y ho\u1ea1t \u0111\u1ed9ng tr\u00ean h\u1ec7 \u0111i\u1ec1u h\u00e0nh 16bit v\u00e0 c\u00f3 t\u00ean g\u1ecdi l\u00e0\u00a0 SQL Server 1.0. \u0110\u00e2y l\u00e0 n\u1ec1n t\u1ea3ng \u0111\u1ec3 ph\u00e1t tri\u1ec3n nh\u1eefng phi\u00ean b\u1ea3n SQL Server m\u1edbi cho \u0111\u1ebfn ng\u00e0y nay. Hi\u1ec7n nay SQL Server \u0111\u00e3 t\u1ed1i \u01b0u h\u01a1n \u0111\u1ec3 v\u1eadn h\u00e0nh trong m\u00f4i tr\u01b0\u1eddng CSDL l\u1edbn v\u00e0 ph\u1ee5c v\u1ee5 \u0111\u01b0\u1ee3c h\u00e0ng ngh\u00ecn ng\u01b0\u1eddi c\u00f9ng s\u1eed d\u1ee5ng trong m\u1ed9t th\u1eddi \u0111i\u1ec3m.\u00a0<\/span><\/p>\n

Tr\u01b0\u1edbc khi t\u00ecm hi\u1ec3u v\u1ec1 l\u1ec7nh SQL JOIN, m\u1ecdi ng\u01b0\u1eddi h\u00e3y t\u00ecm hi\u1ec3u s\u01a1 qua v\u1ec1 th\u00e0nh ph\u1ea7n, t\u00ednh n\u0103ng, phi\u00ean b\u1ea3n c\u1ee7a SQL Server:<\/span><\/p>\n

SQL Server c\u00f3 nh\u1eefng th\u00e0nh ph\u1ea7n n\u00e0o?<\/span><\/h3>\n

M\u1ed9t SQL Server hi\u1ec7n nay \u0111\u01b0\u1ee3c Microsoft thi\u1ebft l\u1eadp d\u1ef1a v\u00e0o 1 c\u1ea5u tr\u00fac d\u1ea1ng b\u1ea3ng bi\u1ec3u. N\u00f3 bao g\u1ed3m nh\u1eefng d\u00f2ng c\u00f3 th\u1ec3 k\u1ebft n\u1ed1i nh\u1eefng d\u1eef li\u1ec7u li\u00ean quan \u1edf nhi\u1ec1u b\u1ea3ng kh\u00e1c nhau. V\u00ec v\u1eady m\u00e0 n\u00f3 \u0111\u00e3 lo\u1ea1i b\u1ecf \u0111\u01b0\u1ee3c nhu c\u1ea7u v\u1ec1 l\u01b0u tr\u1eef c\u00e1c d\u1eef li\u1ec7u t\u1ea1i \u0111a d\u1ea1ng v\u1ecb tr\u00ed trong CSDL<\/span><\/p>\n

Nh\u01b0 v\u1eady SQL Server c\u00f3 2 th\u00e0nh ph\u1ea7n l\u00e0 SQLOS v\u00e0 Database Engine:<\/span><\/p>\n

Database Engine<\/span><\/h4>\n

\u0110\u00e2y l\u00e0 m\u1ed9t th\u00e0nh ph\u1ea7n ch\u00ednh trong SQL Server, ch\u1ee9c n\u0103ng c\u1ee7a Database Engine l\u00e0 x\u1eed l\u00fd, qu\u1ea3n l\u00fd l\u01b0u tr\u1eef, b\u1ea3o m\u1eadt c\u00e1c d\u1eef li\u1ec7u. Th\u00e0nh ph\u1ea7n n\u00e0y c\u0169ng bao g\u1ed3m kh\u00e1 nhi\u1ec1u c\u00f4ng c\u1ee5 nh\u01b0 qu\u1ea3n l\u00fd t\u1ec7p, l\u01b0u tr\u1eef t\u1ec7p, trang, b\u1ea3ng, b\u1ed9 \u0111\u1ec7m ch\u1ee9a d\u1eef li\u1ec7u, ch\u1ec9 m\u1ee5c, giao d\u1ecbch CSDL.<\/span><\/p>\n

\"sql-join-2\"<\/picture>
QL Server c\u00f3 nh\u1eefng th\u00e0nh ph\u1ea7n n\u00e0o?<\/figcaption><\/figure>\n

SQLOS<\/span><\/h4>\n

\u0110\u00e2y l\u00e0 t\u1ea7ng cu\u1ed1i \u1edf trong c\u1ea5u tr\u00fac c\u1ee7a ph\u1ea7n m\u1ec1m Database Engine. SQLOS s\u1ebd x\u1eed l\u00fd nh\u1eefng nhi\u1ec7m v\u1ee5 ch\u00ednh nh\u01b0 l\u00ean l\u1ecbch v\u1ec1 c\u00e1c nhi\u1ec7m v\u1ee5, qu\u1ea3n l\u00fd c\u00e1c b\u1ed9 nh\u1edb, kh\u00f3a c\u00e1c d\u1eef li\u1ec7u \u0111\u1ec3 tr\u00e1nh nh\u1eefng xung \u0111\u1ed9t c\u00f3 th\u1ec3 di\u1ec5n ra khi ng\u01b0\u1eddi d\u00f9ng th\u1ef1c hi\u1ec7n c\u1eadp nh\u1eadt.<\/span><\/p>\n

SQL Server bao g\u1ed3m t\u00ednh n\u0103ng n\u1ed5i b\u1eadt n\u00e0o?<\/span><\/h3>\n

\u0110\u1ec3 hi\u1ec3u r\u00f5 v\u1ec1 l\u1ec7nh SQL JOIN, m\u1ecdi ng\u01b0\u1eddi c\u1ea7n bi\u1ebft SQL Server g\u1ed3m t\u00ednh n\u0103ng n\u00e0o? Microsoft \u0111ang cung c\u1ea5p m\u1ed9t s\u1ed1 t\u00ednh n\u0103ng v\u1ec1 qu\u1ea3n l\u00fd c\u00e1c d\u1eef li\u1ec7u cho SQL Server c\u00f9ng v\u1edbi nh\u1eefng d\u1ecbch v\u1ee5 h\u1ed7 tr\u1ee3 l\u1eadp tr\u00ecnh nh\u01b0 SQL Server Data Quality, SQL Server, SQL Server Master. B\u00ean c\u1ea1nh \u0111\u00f3, SQL Server c\u00f2n cung c\u1ea5p 2 c\u00f4ng c\u1ee5 h\u1ed7 tr\u1ee3 l\u1eadp tr\u00ecnh vi\u00ean v\u00e0 qu\u1ea3n tr\u1ecb CSDL (DBAs):<\/span><\/p>\n