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检查,只对添加约束后有在录入的数据进行检查 Sugar_zxf 欢迎任何形式的转载,但请务必注明出处。 限于本人水平,如果文章和代码有表述不当之处,还请不吝赐教。
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和从表stuMarks建立关系,关联字段为stuNo) alter table 从表 add constraint 约束名 foreign key(关联字段) references 主表(关联字段) --sql server中删除约束的语句是: alter table 表名 drop constrai...
语法:`ADD CONSTRAINT DF_ConstraintName DEFAULT (DefaultValue) FOR ColumnName` 示例 为`CommoditySort` 表添加主键约束: ```sql ALTER TABLE CommoditySort ADD CONSTRAINT PK_Sortld PRIMARY KEY (Sortld); ``` 为`CommodityInfo` 表添加外键约束: ```sql ALTER TABLE CommodityInfo ADD CONSTRAINT FK_Sortl...
In SQL Server, all table constraints are database objects, just like tables, views, stored procedures, functions, and so on. Therefore, constraints must have unique names across the database. But because every table constraint is scoped to an individual table, it makes sense to adopt a naming...
SQL SERVER T_SQL新增字段 [UserLeves] [int] NULL, [LikeNum] [int] NULL, [ToLikeNum] [int] NULL, [ShareNum] [int] NULL, [AttentionNum] [int] NULL, [ToAttentionNum] [int] NULL, [AriticleNum] [int] NULL, [EnableArticleNum] [int] NULL,...
SQL Server 数据库实现之T-SQL语句[备忘] 1、用SQL创建文件夹 用SQL创建文件夹 -- 1、显示高级选项 sp_configure 'show advanced options',1; reconfigure; --更改当前配置 go -- 2、启用 xp_cmdshell: sp_configure 'xp_cmdshell',1; -- 1代表“用户ID”...
alter table 表名add constraint 约束名 check(列名 is not null)
Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Memory-optimized tables, natively compiled stored procedures, and user-defined functions do not support the full Transact-SQL surface area that is supported by disk-based tables, interpreted Transact-SQL stored procedures, and user...
TSqlParserToken TSqlScript TSqlStatement TSqlStatementSnippet TSqlTokenType TSqlTriggerEventGroupHelper TSqlTriggerEventTypeHelper UnaryExpression UnaryExpressionType UniqueConstraintDefinition UniqueRowFilter UnpivotedTableReference UnqualifiedJoin UnqualifiedJoinType UpdateCall UpdateDeleteSpecificationBase UpdateForCl...
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