MySQL的SELECT MIN乘以结果

比约恩C

我有这个查询：

SELECT t1.*, 
       t2.project_time, 
       t3.obj as start_up_obj, 
       t3.casting_meeting_date as start_up_casting, 
       t3.start_up_meeting_date as start_up_meeting_date
FROM table1 as t1
LEFT JOIN table2 as t2 
ON t1.obj = t2.nr
LEFT JOIN table3 as t3 
ON t1.obj = t3.obj
ORDER BY obj_house_floor ASC

通过此查询，我构建了一个包含大量结果的数组。

现在，我想向其添加此查询：

SELECT start_up_meeting 
FROM table1 
WHERE obj = :obj 
ORDER BY start_up_meeting ASC LIMIT 1

我试过了：

SELECT t1.*, 
       t2.project_time, 
       t3.obj as start_up_obj, 
       t3.casting_meeting_date as start_up_casting, 
       t3.start_up_meeting_date as start_up_meeting_date, 
       MIN(t1.start_up_meeting) as min_start_up_meeting
FROM table1 as t1
LEFT JOIN table2 as t2 
ON t1.obj = t2.nr
LEFT JOIN table3 as t3 
ON t1.obj = t3.obj
ORDER BY obj_house_floor ASC

这个查询只会给我数组中的一个结果。
如何添加MIN(t1.start_up_meeting) as min_start_up_meeting所有结果？

他们不是

SELECT t1.*, 
       t2.project_time, 
       t3.obj as start_up_obj, 
       t3.casting_meeting_date as start_up_casting, 
       t3.start_up_meeting_date as start_up_meeting_date,
       t4.min_start_up_meeting
FROM table1 as t1
LEFT JOIN table2 as t2 
  ON t1.obj = t2.nr
LEFT JOIN table3 as t3 
  ON t1.obj = t3.obj
CROSS JOIN ( SELECT MIN(start_up_meeting) min_start_up_meeting
             FROM table1 
             WHERE obj = :obj ) t4
ORDER BY obj_house_floor ASC

我不能使用=：obj我应该在On t1.obj = t4.obj上使用吗？

当然。

SELECT t1.*, 
       t2.project_time, 
       t3.obj as start_up_obj, 
       t3.casting_meeting_date as start_up_casting, 
       t3.start_up_meeting_date as start_up_meeting_date,
       t4.min_start_up_meeting
FROM table1 as t1
LEFT JOIN table2 as t2 
  ON t1.obj = t2.nr
LEFT JOIN table3 as t3 
  ON t1.obj = t3.obj
INNER JOIN ( SELECT obj, 
                    MIN(start_up_meeting) min_start_up_meeting
             FROM table1
             GROUP BY obj ) t4 
  ON t1.obj = t4.obj
ORDER BY obj_house_floor ASC