Oracle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 

1
select * from emp where rowid in (select decode(mod(rownum,2),0,rowid) from emp);

for odd number of records 

1
select*from emp where rowid in (select decode(mod(rownum,2),1,rowid) from emp);

或者

FOR ODD NUMBER OF ROWS 

1
SELECT * FROM emp WHERE rowid IN (SELECT DECODE(MOD(rownum,2),1,rowid,NULL) FROM emp);

FOR EVEN NUMBER OF ROWS 

1
SELECT * FROM emp WHERE rowid IN (SELECT DECODE(MOD(rownum,2),0,rowid,NULL) FROM emp);

方法2用in子查询

Odd number of records: 

1
select * from emp where (rowid,1) in (select rowid, mod(rownum,2) from emp);

Output:- 1 3 5

Even number of records: 

1
select * from emp where (rowid,0) in (select rowid, mod(rownum,2) from emp)

Output:- 2 4 6