1、T-SQL语句添加约束(表中没有数据时): 语法:alter table <表名> add constraint <约束名> <约束类型> <具体的约束说明 > 约束名的取名规则推荐采用:约束类型_约束列 主键(Primary Key)约束:如:PK_UserId 唯一(Unique Key) 约束:如:UQ_UserCardId 默认(Default Key)约束:如 DK_ 检查(Check Key) 约...
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 约束名 check (字段 between 1 and 100 ) ---添加外键约束(主表stuInfo和...
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_Commodity FOREIGN KEY (Commodityld) REFERENCES CommodityInfo (Commodityld)...
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 of the column or combination of columns. 和主键约束一样,唯一性约束自动创建...
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',@...
命名空間:Microsoft.Data.Schema.ScriptDom.Sql 組件:Microsoft.Data.Schema.ScriptDom.Sql (在 Microsoft.Data.Schema.ScriptDom.Sql.dll 中) 語法 VB複製 '宣告PublicOverridableSubVisit ( _ nodeAsDefaultConstraint _ ) 參數 node 型別:Microsoft.Data.Schema.ScriptDom.Sql.DefaultConstraint ...
在SQL SERVER的企业管理器(SQL ENTERPRISEMANAGER)中,选定某一数据库,创建存储过程print_dbstructure。 源代码如下: if exists(select * from sysobjects where id = object_id('dbo. print_dbstructure ') and sysstat& 0xf = 4) 存储过程 drop proceduredbo. print_dbstructure ...
Feature FOREIGN KEY Applies to: Azure SQL Database and SQL Server starting SQL Server 2016 (13.x)For memory-optimized tables, FOREIGN KEY constraints are only supported for foreign keys referencing primary keys of other memory-optimized tables. Remove the constraint from the table definition if th...
Feature FOREIGN KEY Applies to: Azure SQL Database and SQL Server starting SQL Server 2016 (13.x)For memory-optimized tables, FOREIGN KEY constraints are only supported for foreign keys referencing primary keys of other memory-optimized tables. Remove the constraint from the table definition if th...
Remove the constraint from the table definition if the foreign key references a unique constraint.In SQL Server 2014 (12.x), FOREIGN KEY constraints are not supported with memory-optimized tables. Feature clustered index Specify a nonclustered index. In the case of a primary key index be sure...