SQLServer禁用、啟用外鍵約束

---啟用or禁用指定表所有外鍵約束  
alter table PUB_STRU  NOCHECK constraint all;  
alter table PUB_STRU  CHECK constraint all;  
  
---生成啟用or禁用指定表外鍵約束的sql  
select 'ALTER TABLE ' + b.name + ' NOCHECK CONSTRAINT ' + a.name +';'  from sysobjects a ,sysobjects b where a.xtype ='f' and a.parent_obj = b.id and b.name='表名';  
select 'ALTER TABLE ' + b.name + ' CHECK CONSTRAINT ' + a.name +';'  from sysobjects a ,sysobjects b where a.xtype ='f' and a.parent_obj = b.id and b.name='表名';  

--生成的sql如下
ALTER TABLE PUB_STRU NOCHECK CONSTRAINT PUBSTRU_FK1; 
ALTER TABLE PUB_STRU NOCHECK CONSTRAINT PUBSTRU_FK2; 
ALTER TABLE PUB_STRU CHECK CONSTRAINT PUBSTRU_FK1; 
ALTER TABLE PUB_STRU CHECK CONSTRAINT PUBSTRU_FK2;   

 --查看約束狀態（查詢字典表 sys.foreign_keys，該字典表開始出現於sqlserver2005及以上版本）：
select name , is_disabled from sys.foreign_keys order by name;  
 --其中：name  ： 外鍵約束名稱   is_disabled : 是否已禁用

　　

例子：

 --刪除外鍵
alter table AdItem drop constraint AdOrder_AdItem_FK1

--增加外鍵
alter table AdItem 
add constraint AdOrder_AdItem_FK1 foreign key (AI_nOrderNo) references AdOrder(AO_nOrderNo)

--單個表的一個外鍵
alter table Student nocheck constraint FK__Student__SchoolN__4222D4EF  
alter table Student check constraint FK__Student__SchoolN__4222D4EF  

--單個表的所有外鍵
alter table Student nocheck constraint all  
alter table Student check constraint all  

--某個數據庫的所有表
EXEC sp_MSforeachtable @command1='alter table ?  NOCHECK constraint all;
EXEC sp_MSforeachtable @command1='alter table ?  CHECK constraint all;

 

參考：
 Enable/Disable Constraint in SQLServer 
 sp_MSforeachtable使用方法