唯一(Unique Key) 约束:如:UQ_UserCardId 默认(Default Key)约束:如 DK_ 检查(Check Key) 约束: 如 CK_ 外键(Foreign Key)约束: 如 FK_ 2、 T-SQL语句添加约束(表中有数据时): 语法:alter table <表名> with nocheck add constraint <约束名> <约束类型> <具体的约束说明> 对表中现有的数据不做...
alter table 表名 add constraint 约束名 primary key (主键) --添加唯一约束 alter table 表名 add constraint 约束名 unique (字段) ---添加默认约束 alter table 表名 add constraint 约束名 default ('默认内容') for 字段 --添加检查check约束,要求字段只能在1到100之间 alter table 表名 add constraint...
假设有 T-SQL 为:ALTER TABLE ABC ADD CONSTRAINTPRIMARYKEYS CHECK(CH>300),则它的执行结果是( ) A. 为表ABC添加主键约束,并且字段 CH的值必须大于300 B. 为表ABC添加检查约束,约束名为 PRIMARYKEYS C. 为表ABC添加约束,规定字段 CH为主键 D. 为表ABC添加一个字段CH,并且字段CH的值必须大于300 E. ...
ADD CONSTRAINT CK_Gender CHECK (Gender = 0 OR Gender = 1), ADD CONSTRAINT DF_Gender DEFAULT (0) FOR Gender; ``` 为`OrderInfo` 表添加外键约束和默认值约束: ```sql ALTER TABLE OrderInfo ADD CONSTRAINT FK_Userld FOREIGN KEY (Userld) REFERENCES UserInfo (Userld), ADD CONSTRAINT FK_Commodit...
SQL 复制 CREATE TABLE [dbo].[T1] ( [c1] [int] NOT NULL, [c2] [float] NOT NULL, CONSTRAINT [PK_T1] PRIMARY KEY NONCLUSTERED ([c1]) ) WITH ( MEMORY_OPTIMIZED = ON , DURABILITY = SCHEMA_AND_DATA ) GO CREATE PROCEDURE [dbo].[usp_1] WITH NATIVE_CO...
ALTER TABLE [dbo].[E_CMS_Community_Statistics] ADD CONSTRAINT [DF__E_CMS_Com__Delet__2B947552] DEFAULT ((0)) FOR [DeleteToLikeNum] GO EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'用戶ID' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@...
ALTERTABLEProduction.CategoriesADDCONSTRAINTUC_CategoriesUNIQUE(categoryname); GO Like the primary key constraint, the unique constraint automatically creates a unique index with the same name as the constraint. By default, the index will be nonclustered. SQL uses that index to enforce the uniqueness ...
AlterTableAddTableElementStatement AlterTableAlterColumnOption AlterTableAlterColumnStatement AlterTableAlterIndexStatement AlterTableAlterPartitionStatement AlterTableChangeTrackingModificationStatement AlterTableConstraintModificationStatement AlterTableDropTableElement AlterTableDropTableElementStatement AlterTable...
命名空間: Microsoft.SqlServer.TransactSql.ScriptDom 組件: Microsoft.SqlServer.TransactSql.ScriptDom (在 Microsoft.SqlServer.TransactSql.ScriptDom.dll 中)語法VB 複製 '宣告 Public Overridable Sub ExplicitVisit ( _ node As DefaultConstraintDefinition _ ) '用途 Dim instance As TSqlFragmentVisitor Dim ...
AlterTableAddTableElementStatement AlterTableAlterColumnOption AlterTableAlterColumnStatement AlterTableAlterIndexStatement AlterTableAlterPartitionStatement AlterTableChangeTrackingModificationStatement AlterTableConstraintModificationStatement AlterTableDropTableElement AlterTableDropTableElementStatement ...