--启用or禁用指定表所有外键约束   
alter table tbname  NOCHECK constraint all  
alter table tbname  CHECK constraint all

--查看约束
select name , is_disabled from sys.foreign_keys order by name

--禁用
ALTER TABLE tbname DISABLE TRIGGER trigname

--恢复
ALTER TABLE tbname ENABLE TRIGGER trigname

--禁用某个表上的所有触发器
ALTER TABLE tbname DISABLE TRIGGER all
 
--启用某个表上的所有触发器
ALTER TABLE tbname ENABLE TRIGGER all

--添加主键
alter table tbname add constraint pk_name primary key(column1,column2)
--添加非聚集主键
alter table tbname add constraint pk_name primary key NONCLUSTERED(column1,column2)
--删除主键
alter table tbname drop constraint pk_name

--添加外键
alter table tbname add constraint fk_name foreign key (fk_column) references pk_tbname(pk_column)
--删除外键
alter table tbname drop constraint fk_name

--添加唯一约束
alter table tbname add constraint uq_colname unique (colname)