查询[start,start+limit],包含start,包含start+limit,如start=21,limit=10结果就是21到30,包含21和30SELECT * FROM (SELECT A.*, rownum rn FROM (SELECT * FROM tableName ORDER BY time DESC ) A WHERE rownum <= start + limit ) B WHERE rn >= start;…
select t2.* from --两层嵌套 (select t.* , rownum as row_numfrom t where rownum <=20) t2 where t2.row_num > 11 select t3.* from ( --三层嵌套select t2.*, rownum as row_num from (select * from t) t2 where rownum<=20) t3 where t2.row_num>11 两层嵌套 ==三…
关于分页写法的性能分析及ROWNUM的补充说明 分页写法 一.测试前数据准备 SQL> SELECT COUNT(*) FROM BPM_PROCVAR; COUNT(*) ---------- 1.分页写法一 SELECT * FROM (SELECT ROWNUM RN, A.* FROM (SELECT * FROM BPM_PROCVAR ORDER BY VARID) A ) B ; 查询结果:20条记录,查询时间:0.031秒 2.分页写法二 SELECT * FROM (SELEC…
ROWNUM的知识点 A ROWNUM依照oracle的默认机制生成. B rownum仅仅能使用<= <号,不能使用> >= rownum的实现机制 rownum表示,返回的结果集的行号(是一个属性,固化到一行之中.不会由于你排序,而发生变化).没有第一行,就没有第二行:没有第二行就没有第三行. Oracle Top-N select rownum,empno,ename,sal from (select empno,ename,sal from emp order b…
SqlServer 分页语句 select StuID ,StuNo,StuName,Age,Sex, ClassName ClassName from (select *, row_number() over (order by StuID asc) as number from StudentInfo) t ,ClassInfo c where t.ClassID = c.ClassID and t.number between @startindex and @endindex 表1==C…