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mysql
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select * from table_name limit 从第几条取,取几条
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sql server
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select top 4 * from 表名 where not in(select top 4 * from 表名 where 条件);
排除前4条，再取4条
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oracle
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--第一层
select * from emp;
--第二层
select t1.*,rownum rn from (select * from emp) t1 where rownum<=12;
--第三层
select t2.* from (select t1.*,rownum rn from (select * from emp) t1 where rownum<=10) t2 where t2.rn>=6;
int startIndex; 开始位置
int pageSize; 取的条数
select t2.* from (select t1.*,rownum rn from (select * from emp) t1 where rownum<=(startIndex*pageSize)) t2 where t2.rn>=((startIndex-1)*pageSize+1);
测试：
--创建新表查入另一张表的数据
create table mytest as select empno,ename,job,sal,comm from emp;
--自我赋值数据[多次执行]
insert into mytest(empno,ename,job,sal,comm) select * from mytest;
select t2.* from (select t1.*,rownum rn from (select * from emp) t1 where rownum<=10) t2 where t2.rn>=6;
select t2.* from (select t1.*,rownum rn from (select * from emp) t1 where rownum<=300010) t2 where t2.rn>=300000;
分别查看所执行的时间
