sql 分页
2010-05-18 15:09 贺臣 阅读(808) 评论(1) 编辑 收藏 举报1.分页方案一:(利用Not In和SELECT TOP分页)效率次之
语句形式:
SELECT TOP 10 * FROM TestTable
WHERE(ID NOT IN (SELECT TOP 20 id FROM TestTable ORDERBY id)) ORDERBYID
SELECT TOP 页大小 * FROM TestTable
WHERE( ID NOT IN (SELECT TOP 每页大小-1*待查询页数-1 id FROM 表 ORDERBY id)) ORDERBYID
思路:先查询出待查询页之前的全部条数的id,查询ID不在这些ID中的指定数量条数
2.分页方案二:(利用ID大于多少和SELECT TOP分页)效率最高
语句形式:
SELECT TOP 10 * FROM TestTable
WHERE(ID> (SELECT MAX(id) FROM(SELECT TOP20 id FROM TestTable ORDERBYid)AST))ORDERBYID
SELECT TOP 页大小* FROM TestTable
WHERE(ID>(SELECTMAX(id)FROM(SELECT TOP 每页大小*待查询页数-1 id FROM表 ORDERBYid)AST)) ORDERBYID
思路:先获得待查询页的之前全部条数id,获得它们当中最大的ID号,以此最大ID号为标志,查找比这个ID号大的指定条数
3.分页方案三:
SELECT TOP PageSize * FROM(SELECT TOP nPage*PageSize * from YOURTABLE order by id)as a order by id desc
SELECT TOP 每页条数 * FROM (SELECT TOP 待查询页*每页条数) * from YOURTABLE order by id)as a order by id desc
思路:先正排序查询出待查询页之前(包括当前页)的全部条数,然后将其倒排序,取指定条数
4.分页方案四:
(利用SQL的游标存储过程分页)
create procedureSqlPager
@sqlstrnvarchar(4000),--查询字符串
@currentpageint,--第N页
@pagesizeint--每页行数
as
setnocounton
[email=[ft=,2,]declare@P1int,--P1]declare@P1int,--P1[/email]是游标的id
@rowcountint
[email=execsp_cursoropen@P1output,@sqlstr,@scrollopt=1,@ccopt=1,@rowcount=@rowcountoutput]execsp_cursoropen@P1output,@sqlstr,@scrollopt=1,@ccopt=1,@rowcount=@rowcountoutput[/email]
selectceiling([email=[ft=,2,]1.0*@rowcount/@pagesize)as]1.0*@rowcount/@pagesize)as[/email]总页数--,@rowcountas总行数,@currentpageas当前页
[email=set@currentpage=(@currentpage-1)*@pagesize+1]set@currentpage=(@currentpage-1)*@pagesize+1[/email]
[email=[ft=,2,]execsp_cursorfetch@P1,16,@currentpage,@pagesize]execsp_cursorfetch@P1,16,@currentpage,@pagesize[/email]
[email=[ft=,2,]execsp_cursorclose@P1]execsp_cursorclose@P1[/email]
setnocountoff
其它的方案:如果没有主键,可以用临时表,也可以用方案三做,但是效率会低。
建议优化的时候,加上主键和索引,查询效率会提高。
1.Oracle:
select * from ( select row_.*, rownum rownum_ from ( query_SQL ) row_ where rownum =< max) where rownum_ >= min
2.SQL Server:
select top @pagesize * from tablename where id not in (select top @pagesize*(@page-1) id from tablename order by id) order by id
3.MySQL
select * from tablename limit position, counter
4.DB2
select * from (select *,rownumber() as ROW_NEXT from tablename) where ROW_NEXT between min and max