SQL Server游標語句使用方法:
復制代碼 代碼如下:
--聲明一個游標
DECLARE MyCursor CURSOR
FOR SELECT TOP 5 FBookName,FBookCoding FROM TBookInfo//定義一個叫MyCursor的游標,存放for select 后的數(shù)據(jù)
--打開一個游標
OPEN MyCursor//即打開這個數(shù)據(jù)集
--循環(huán)一個游標
DECLARE @BookName nvarchar(2000),@BookCoding nvarchar(2000)
FETCH NEXT FROM MyCursor INTO @BookName,@BookCoding//移動游標指向到第一條數(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
--關閉游標
CLOSE MyCursor
--釋放資源
DEALLOCATE MyCursor
eg:
復制代碼 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

游標屬于行級操作 消耗很大 SQL查詢是基于數(shù)據(jù)集的所以一般查詢能有 能用數(shù)據(jù)集 就用數(shù)據(jù)集 別用游標 數(shù)據(jù)量大 是性能殺手