返回奇数行或者偶数行数据库表记录
－－方法1用Decode函数
for even number of records
select*from emp where rowid in(select decode(mod(rownum,2),0,rowid) from emp);
for odd number of records
select*from emp where rowid in(select decode(mod(rownum,2),1,rowid) from emp);
或者：
FOR ODD NUMBER OF ROWS
SELECT*FROM emp WHERE rowid IN(SELECT DECODE(MOD(rowid,2),1,rowid,NULL)FROM emp);
FOR EVEN NUMBER OF ROWS
SELECT*FROM emp WHERE rowid IN(SELECT DECODE(MOD(rowid,2),0,rowid,NULL) FROM emp);
－－方法2用 in 子查询
Odd number of records:
select * from emp where (rowid,1) in (select rowid, mod(rownum,2) from emp);
Output:-
1
3
5
Even number of records:
select * from emp where (rowid,0) in (select rowid, mod(rownum,2) from emp)
Output:-
2
4
6
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