Question

我有两个表，节目和对象。我想打印出最新的对象，以及它们的显示名称。现在我这样做：

SELECT MAX(objects.id) as max_id, shows.name, shows.id 
FROM shows, objects 
WHERE shows.id = objects.showId
GROUP BY shows.name

但是，如果我还想获取对象的剧集我不能像SELECT object.episode [...]那样，因为那时候不会自动选择MAX(objects.id)的对象，所以我的问题是怎么做？

如果你还没有找到我的表，他们会是这样的：

节目
- 编号
- 名称

还有：

物件
- 编号
- 名称
- 集
- 季
- showId

使用MySQL。

Answer 1

像这样（未经测试）：

SELECT objects.id as max_id, objects.episode, shows.name, shows.id
  FROM shows, objects 
 WHERE shows.id = objects.showId
   AND objects.id = (
        SELECT MAX(id) FROM objects
         WHERE name = shows.name
       )

Answer 2

SELECT objects.id as max_id, shows.name, shows.id 
FROM shows, objects 
WHERE shows.id = objects.showId
ORDER BY objects.id DESC
GROUP BY shows.name 
LIMIT 1

这样做你需要的吗？

Answer 3

我觉得这样的事情也会起作用：

SELECT objects.id, objects.episode, shows.name, shows.id 
FROM shows 
JOIN objects AS objects_for_max ON shows.id = objects.showId
JOIN objects ON objects.id=MAX(objects_for_max.id)
GROUP BY shows.name

加入时棘手的SQL

3 个答案: