前进中的蜗牛

番茄大叔

水滴穿石,非一日之功;没有量变,何来质变。

游标

游标的定义

游标的实质是一种能从包括多条数据记录的结果集中每次提取一条记录的机制。
游标中包括结果集和游标位置两个内容。

游标的使用步骤

  1. 声明游标
declare cursor_test cursor for
select Number,Name,Age from Student
for read only 
  1. 打开游标
    open cursor_test
  2. 读取
fetch next from cursor_test into @Number,@Name,@Age
while @@FETCH_STATUS = 0
begin 
	print @Number +'   ' + @Name;
	
	fetch next from cursor_test into @Number,@Name,@Age
end
  1. 关闭游标
    close cursor_test
  2. 释放游标
    deallocate cursor_test

完整代码

declare @Number nvarchar(50);
declare @Name  nvarchar(10);
declare @Age int;
declare cursor_test cursor for
select Number,Name,Age from Student
for read only
open cursor_test
fetch next from cursor_test into @Number,@Name,@Age
while @@FETCH_STATUS = 0
begin 
	print @Number +'   ' + @Name;
	
	fetch next from cursor_test into @Number,@Name,@Age
end
close cursor_test
deallocate cursor_test

总结

当然游标还分为:动态游标、只进游标、键集驱动游标,还有游标声明时指明只读或修改,相信你根据你的需求定制。

posted @ 2017-09-22 11:47  LoveTomato  阅读(140)  评论(0编辑  收藏  举报