基于游标的定位DELETE/UPDATE语句

如果游标是可更新的（也就是说，在定义游标语句中不包括Read Only 参数）,就可以用游标从游标数据的源表中DELETE/UPDATE行，即DELETE/UPDATE基于游标指针的当前位置的操作；
举例：
--删除当前行的记录
Declare cur_Depart Cursor
For Select cDeptID,cDeptName From Department into @DeptID,@DeptName
Open cur_Depart
Fetch From cur_Depart into @DeptID,@DeptName
Delete From Department Where CURRENT OF cur_Depart
--更新当前行的内容
Declare cur_Depart Cursor
For Select cDeptID,cDeptName From Department into @DeptID,@DeptName
Open cur_Depart
Fetch From cur_Depart into @DeptID,@DeptName
Update Department Set cDeptID='2007' + @DeptID Where CURRENT OF cur_Depart

 

一个Update例子

create table t1
(
id int
)

--插入数据，这里插入奇数
declare @i int
select @i = 0
while (@i < 100)
begin
    insert into t1 select @i * 2 +1
    select @i = @i + 1
end

--游标处理
declare @ii int
declare @k int
select @k = 1,@ii = 1

declare c_update_id cursor for
select id from t1
for update

open c_update_id

fetch next from c_update_id into @ii
while(@@fetch_status=0)
begin
    update t1 set id = @k where current of c_update_id   

    fetch next from c_update_id into @ii
    select @k = @k + 1
end

CLOSE c_update_id
DEALLOCATE c_update_id

--查询
select * from t1

--删除环境
drop table t1