Question

想问一下在Oracle中当查询出为空时我想显示为其它值要怎么做？

就是当某个字段查询为空值，我不想它为空，想直接在查询结果中显示为其它值，要怎么写？

比如，下面这个语句：
SELECT q.route_name, q.route_date, q.route_price, t.countnum, t.start_time
FROM quota q left outer join v_panicinfo_num t on
q.route_date = t.start_time
where q.route_name = '三亚湾亚太国际会议中心暨三亚海航度假酒店豪华山景房双飞五日自由行' order by q.route_date

我想要t.countnum查询为空时显示为0要怎么做？

Answer 1

SELECT q.route_name, q.route_date, q.route_price, NVL(t.countnum,0), t.start_time
FROM quota q left outer join v_panicinfo_num t on
q.route_date = t.start_time
where q.route_name = '三亚湾亚太国际会议中心暨三亚海航度假酒店豪华山景房双飞五日自由行' order by q.route_date