如: JOB 表里有一个最后更新时间字段: LASTUPDDTTM , 另外一个表 PERS_DATA 中也有一个LASTUPDTTM ,两个表用同一个字段EMPLID 关联 ,SELECT * FROM JOB J,PERS_DATA P WHERE P.EMPLID=J.EMPLID AND J.EMPLID='010804' ,现在想通过SQL语句 比较 两表中同一个EMPLID值所查询的 LASTUPDTTM 值,取出时间大的那个值
thanks , 在线等
thanks , 在线等
没有想到用DECODE ,一直在用CASE 再试
case
when max(J.LASTUPDTTM) - max(P.LASTUPDTTM) > 0 then
max(J.LASTUPDTTM)
else
max(P.LASTUPDTTM)
end as LASTUPDTTM
FROM JOB J, PERS_DATA P
WHERE P.EMPLID = J.EMPLID
AND J.EMPLID = '010804'
case
when max(J.LASTUPDTTM) - max(P.LASTUPDTTM) > 0 then
max(J.LASTUPDTTM)
else
max(P.LASTUPDTTM)
end as LASTUPDTTM
FROM JOB J, PERS_DATA P
WHERE P.EMPLID = J.EMPLID
AND J.EMPLID = '010804'
group by J.EMPLID