[英]Return min value from query with inner join
我有两个表:
表兴趣点:
巴黎| rt_1
米兰| rt_2
罗马| rt_3
表rtgitems:
rt_1 | 22
rt_2 | 3
rt_3 | 3
rt_4 | 5
我希望第一张表的属性NAME在第二张表的总值中具有最小值。 例如:米兰,罗马。
我使用以下查询:
SELECT POI.Name FROM POI INNER JOIN rtgitems ON POI.Vote=rtgitems.item WHERE POI.Vote = (SELECT MIN(rtgitems.totalrate) FROM rtgitems)
但不起作用,我的结果是空的。 我该怎么办? 谢谢。
SELECT POI.Name, min(totalrate) FROM POI INNER JOIN rtgitems ON POI.Vote=rtgitems.item
GROUP BY POI.Name
每当您在sql中使用min或max kind或函数时,都应使用group by子句从表中获取实际输出。
SELECT POI.Name FROM POI INNER JOIN rtgitems ON POI.Vote=rtgitems.item where totalrate= (select min(totalrate) from rtgitems)
GROUP BY POI.Name
希望能帮助到你。
尝试SELECT POI.name FROM POI join rtgitems ON POI.vote=rtgitems.item where totalrate<=(SELECT totalrate from rtgitems order by totalrate desc limit 1)
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.