default_constraints WHERE parent_object_id=912162445 SQL Copy Here we get the constraints name that we have created. Now we are able to drop the constraints by using the above name. alter table STUDENT_DETAILS drop constraint DF__STUDENT_D__IS_RE__3846C6FF SQL Copy Now we are able to ...
使用SQL Server Management Studio 使用Transact-SQL 后续步骤 适用于:SQL Server 2016 (13.x) 及更高版本 Azure SQL 数据库 Azure SQL 托管实例可以使用 SQL Server Management Studio 或 Transact-SQL 在 SQL Server 中删除外键约束。 删除外键约束时,将删除强制引用完整性的要求。外键...
You can implement error handling for the DELETE statement by specifying the statement in aTRY...CATCHconstruct. TheDELETEstatement may fail if it violates a trigger or tries to remove a row referenced by data in another table with aFOREIGN KEYconstraint. If theDELETEremoves multiple rows, and ...
You can implement error handling for the DELETE statement by specifying the statement in aTRY...CATCHconstruct. TheDELETEstatement may fail if it violates a trigger or tries to remove a row referenced by data in another table with aFOREIGN KEYconstraint. If theDELETEremoves multiple rows, and ...
3. Cascade delete, SQL Server 有自带的 cascade delete 功能, principal 被删除, foreign 也一起被删除 4. Restrict delete, 除了 cascade delete, 也可以设置约束, 一旦有 foreign, principal 就不能被删除. (这个是默认行为) 5. Foreign constraint, 当输入一个不存在的 foreign key, SQL Server 会报错....
Note: Indexes created as a result ofPrimary KeyorUniqueKeyconstraints cannot be deleted using the above methods. The constraint has to be deleted to delete the index. Delete Index using SSMS Step 1: Open SSMS. Connect to the database. ...
The only unique constraint onTABLE1is defined oncol1through a primary key constraint. Assume that you have one record (1,1,'Dallas'). When you execute this code: SQL UPDATETABLE1setcol1 =3wherecol3 ='Dallas' TheUPDATEstatement is implemented by SQL Server as a pair ofDELETE/INSERTsta...
The only unique constraint onTABLE1is defined oncol1through a primary key constraint. Assume that you have one record (1,1,'Dallas'). When you execute this code: SQL UPDATETABLE1setcol1 =3wherecol3 ='Dallas' TheUPDATEstatement is implemented by SQL Server as a pair of...
inserted as a result of a delete operation on the table. If a generated column is defined as part of a unique or primary key, parent key in a referential constraint, or unique index, it is possible that an automatic insert will violate a constraint or index in which case an error is ...
DefaultConstraintDefinition DefaultLiteral DelayedDurabilityDatabaseOption DelayedDurabilityOptionKind DeleteMergeAction DeleteSpecification DeleteStatement DeleteUpdateAction DenyStatement DenyStatement80 DeviceInfo DeviceType DialogOption DialogOptionKind DiskStatement DiskStatementOption DiskStatementOptionKind ...