我正在制作一个不起作用的查询。我想在all_destination表中获取图片列的数据,也在查询中使用加入:
SELECT *
FROM `travels_detail`
INNER JOIN all_destination ON travels_detail.destination = all_destination.destination
WHERE all_destination.pic IS NOT NULL
我的查询中有什么问题?
您应该检查MySQL返回的错误。它会告诉您什么是错误。
您只想删除IS NOT NULL
检查,只有
SELECT *
FROM `travels_detail`
INNER JOIN all_destination ON travels_detail.destination = all_destination.destination
WHERE all_destination.pic;
这只会返回设置all_destination.pic
的记录。
尝试以下:
SELECT td.some_attribute
FROM travels_detail as td
INNER JOIN all_destination as ad ON td.destination = ad.destination
WHERE ad.pic IS NOT NULL
您可以尝试一下。
SELECT * FROM `travels_detail` INNER JOIN all_destination ON travels_detail.destination = all_destination.destination WHERE all_destination.pic ! = ""