SQL Server游標(biāo)語(yǔ)句使用方法:
復(fù)制代碼 代碼如下:
--聲明一個(gè)游標(biāo)
DECLARE MyCursor CURSOR
FOR SELECT TOP 5 FBookName,FBookCoding FROM TBookInfo//定義一個(gè)叫MyCursor的游標(biāo),存放for select 后的數(shù)據(jù)
--打開(kāi)一個(gè)游標(biāo)
OPEN MyCursor//即打開(kāi)這個(gè)數(shù)據(jù)集
--循環(huán)一個(gè)游標(biāo)
DECLARE @BookName nvarchar(2000),@BookCoding nvarchar(2000)
FETCH NEXT FROM MyCursor INTO @BookName,@BookCoding//移動(dòng)游標(biāo)指向到第一條數(shù)據(jù),提取第一條數(shù)據(jù)存放在變量中
WHILE @@FETCH_STATUS =0//如果上一次操作成功則繼續(xù)循環(huán)
BEGIN
print 'name'+@BookName
FETCH NEXT FROM MyCursor INTO @BookName,@BookCoding//繼續(xù)提下一行
END
--關(guān)閉游標(biāo)
CLOSE MyCursor
--釋放資源
DEALLOCATE MyCursor
eg:
復(fù)制代碼 代碼如下:
create table #a
(
id varchar(20),
name varchar(20)
)
insert into #a select 1,'jack'
insert into #a select 2,'join'
insert into #a select 3,'make'
declare mycursor cursor
for select * from #a
open mycursor
declare @id varchar(20),@name varchar(20)
fetch next from mycursor into @id,@name
while @@fetch_status=0
begin
select @id,@name
fetch next from mycursor into @id,@name
end
close mycursor
deallocate mycursor
![SQL Server游標(biāo)語(yǔ)句 聲明/打開(kāi)/循環(huán)_腳本之家](http://img.jbzj.com/file_images/article/201304/2013042518024372.jpg)
游標(biāo)屬于行級(jí)操作 消耗很大 SQL查詢(xún)是基于數(shù)據(jù)集的所以一般查詢(xún)能有 能用數(shù)據(jù)集 就用數(shù)據(jù)集 別用游標(biāo) 數(shù)據(jù)量大 是性能殺手