删除数据改成了查询,方便实验。执行原理请详述!
select rowid,e.*
from scott.emp e
where rowid >
(select min(x.rowid) from scott.emp x where x.deptno = e.deptno);
select rowid,e.*
from scott.emp e;
结果是14条数据;
select rowid,e.*
from scott.emp e
where rowid >
(select min(x.rowid) from scott.emp x where x.deptno = e.deptno);
结果是11条数据;
select rowid,e.*
from scott.emp e
where rowid > 'AAAMfPAAEAAAAAgAAA';
结果是13条数据;
select min(x.rowid) from scott.emp x, scott.emp e where x.deptno = e.deptno;
结果是'AAAMfPAAEAAAAAgAAA';
是最后一个查询有问题吗?
select rowid,e.*
from scott.emp e
where rowid >
(select min(x.rowid) from scott.emp x where x.deptno = e.deptno);
结果是11条数据;
select rowid,e.*
from scott.emp e
where rowid > 'AAAMfPAAEAAAAAgAAA';
结果是13条数据;
select rowid,e.*
from scott.emp e;
结果是14条数据;
最後一个应该是表的所有数据数量,第二个语句是'>'所以不包含最小的一条信息,你用'>='应该就是14条信息,第一个语句我没有你的数据没法判断,要看看你执行其中的select min(x.rowid) from scott.emp x where x.deptno = e.deptno语句得出的结果是什麽
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