对于3,需要使用on delete cascade建立外键约束。实验: alter table emp_test add constraint fk_emp_dept_test foreign key(dept) references dept_test(deptno) on delete cascade; delete from dept_test where deptno = 1; 1 row deleted. SQL> select * from dept_test; DEPTNO DEPTNAME --- --- 2 ...
对于3,需要使用on delete cascade建立外键约束。实验: alter table emp_test add constraint fk_emp_dept_test foreign key(dept) references dept_test(deptno) on delete cascade; delete from dept_test where deptno = 1; 1 row deleted. SQL> select * from dept_test; DEPTNO DEPTNAME --- --- 2 ...
对于3,需要使用on delete cascade建立外键约束。实验: alter table emp_test add constraint fk_emp_dept_test foreign key(dept) references dept_test(deptno) on delete cascade; delete from dept_test where deptno = 1; 1 row deleted. SQL> select * from dept_test; DEPTNO DEPTNAME --- --- 2 ...
因此,可以将 ANSI_NULL_DFLT_OFF 或 ANSI_NULL_DFLT_ON 设置为 ON,或者将二者都设置为 OFF。 如果有一个选项为 ON,则该设置(SET ANSI_NULL_DFLT_OFF 或 SET ANSI_NULL_DFLT_ON)生效。 如果将这两个选项都设置为 OFF,则 SQL Server 将使用 sys.databases 目录视图中 is_ansi_null_default...
`status` varchar( 20 ) NOT NULL , `notes` text, KEY ( sector_id ) , FOREIGN KEY ( sector_id ) REFERENCES client_sectors( sector_id ) ON DELETE SET NULL ) ENGINE = innodb MySQL said: Documentation #1005 - Can't create table '.\isimo_net_demo\clients.frm' (errno: 150...
DELETE FROM instructor WHERE dept_name='Finance'; /*常见的两个表之间进行删除*/ DELETE FROM instructor WHERE dept_name IN (SELECT dept_name FROM department WHERE building ='Watson'); 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. insert:插入操作。
SQL 复制 CREATE EVENT SESSION [alwayson_health] ON SERVER ADD EVENT data_movement_suspend_resume ( WHERE ( [suspend_status] = (SUSPENDED) OR [suspend_status] = (SUSPENDED_INVALID) OR [suspend_status] = (SUSPEND_NULL) ) ) ADD TARGET package0.event_file ( SET filename = N'alway...
使用Get-ClusterResourceCmdlet 尋找網路名稱資源,再使用Set-ClusterParameterCmdlet 設定HostRecordTTL值,如下所示: Get-ClusterResource "<NetworkResourceName>" | Set-ClusterParameter HostRecordTTL<TimeInSeconds> 下列PowerShell 範例會針對名為SQL Network Name (SQL35)的網路名稱資源將 HostRecordTTL 設定為 300...
C++_delete主外键关联删除(on delete set null和on delete cascade)触发器 是一种特殊类型的存储过程，...
I'm using the INNO DB storage engine. The sector_id columns is indexed in both tables. sector_id in the clients table allows nulls. I just don't get it. Hope you can help. Thanks, Sean Subject Written By Posted Foreign Key ON DELETE SET NULL ...