SQl 游标

declare @id nvarchar(20)

 DECLARE My_Cursor CURSOR --定义游标

FOR (select autoid from U_VoucherItems where CardNum='k006' and CardSection='B') --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 @id; --读取第一行数据

 WHILE @@FETCH_STATUS = 0

 BEGIN      

     update U_VoucherItems set CardItemNum=(select MAX(CardItemNum)+1 from U_VoucherItems where CardNum='k006' and CardSection='B'

     ) where CardNum='k006' and autoid=@id

 

 FETCH NEXT FROM My_Cursor  INTO @id; --读取第一行数据

 

    END

CLOSE My_Cursor; --关闭游标

DEALLOCATE My_Cursor; --释放游标

来源：https://www.cnblogs.com/su-king/p/5121866.html