SQLSERVER 批量去掉外键约束

DECLARE @SQLSTR VARCHAR(1000);
DECLARE My_Cursor CURSOR --定义游标 
FOR (select  ‘ALTER TABLE ‘+o.name+‘ drop  CONSTRAINT ‘+fk.name+‘;‘  AS  Command  from   sys.foreign_keys  fk    JOIN  sys.all_objects  o  ON fk.parent_object_id=o.object_id) --查出需要的集合放到游标中 
OPEN My_Cursor; --打开游标 
FETCH NEXT FROM My_Cursor INTO @SQLSTR; --读取第一行数据 
WHILE @@FETCH_STATUS = 0 
  BEGIN 
  exec(@SQLSTR);
  --UPDATE dbo.MemberAccount SET UserName = UserName + ‘A‘ WHERE CURRENT OF My_Cursor; --更新 
 --DELETE FROM dbo.MemberAccount WHERE CURRENT OF My_Cursor; --删除 
 FETCH NEXT FROM My_Cursor INTO @SQLSTR; --读取下一行数据 
 END 
CLOSE My_Cursor; --关闭游标 
DEALLOCATE My_Cursor; --释放游标 
GO