SQL删除数据库中所有用户数据表外键

--SQL删除数据库中所有用户数据表外键

--查询删除前的当前数据库所有约束

select * from information_schema.key_column_usage

declare @TableName nvarchar(250)

--声明读取数据库所有数据表名称游标mycursor1

declare mycursor1 cursor for select name from dbo.SysObjects WHERE OBJECTPROPERTY(ID, 'IsUserTable') = 1

--打开游标

open mycursor1

--从游标里取出数据赋值到我们刚才声明的数据表名变量中

fetch next from mycursor1 into @TableName

--如果游标执行成功

while (@@fetch_status=0)

begin

--定义当前外键约束变量

declare @ConstraintName varchar (200)

--删除当前数据表的所有外键约束

--声明读取数据表所有外键约束名称游标mycursor2

declare mycursor2 cursor for select name from dbo.sysobjects where Xtype = 'F' and Parent_Obj = (select [ID] from dbo.sysobjects where id = object_id(N'['+@TableName+']') and OBJECTPROPERTY(id, N'IsUserTable') = 1)

--打开游标

open mycursor2

--从游标里取出数据赋值到外键约束名称变量中

fetch next from mycursor2 into @ConstraintName

--如果游标执行成功

while (@@fetch_status=0)

begin

--删除当前找到的外键

exec ('ALTER TABLE '+@TableName+' DROP CONSTRAINT
'+@ConstraintName)

--print 'ALTER TABLE '+@TableName+' DROP CONSTRAINT
'+@ConstraintName

--用游标去取下一条记录

fetch next from mycursor2 into @ConstraintName

end

--关闭游标

close mycursor2

--撤销游标

deallocate mycursor2

--用游标去取下一条记录

fetch next from mycursor1 into @TableName

end

--关闭游标

close mycursor1

--撤销游标

deallocate mycursor1

--查询删除后的当前数据库所有约束

select * from information_schema.key_column_usage