对表1请求中的表2中的用户进行计数


Count users from table 2 in request to table 1

我有一个位置表

tbl_positions
   id position
    1 Driver
    2 Lobby
    3 Support
    4 Constructor 

在另一个表中我有users

tbl_workers
  id   name   position status
   1   John   2        3
   2   Mike   3        2
   3   Kate   2        3
   4   Andy   1        0

i do request of positions

如果没有status,我选择这个查询的所有内容。

SELECT p.id, p.position, count(*) FROM  tbl_positions as p
inner join tbl_workers as w on w.position=p.id
group by p.id, p.position

但现在我需要输出相同的查询,但也考虑状态,状态2=预订状态,3=放置。我需要在单个查询中得到这样的输出。

Position    booked placed
Driver        0       0
Lobby         0       2
Support       1       0
Constructor   0       0

我尝试添加WHERE tbl_workers.status IN (2)用于预订和WHERE tbl_workers.status IN (3)用于放置,它在两个查询中工作,但没有运气将此加入一个查询

试试这个:

SELECT p.id, 
    p.position, 
    SUM(CASE w.Status WHEN 2 THEN 1 ELSE 0 END)  AS booked,
    SUM(CASE w.Status WHEN 3 THEN 1 ELSE 0 END)  AS placed
  FROM  tbl_positions AS p LEFT JOIN tbl_workers AS w 
      ON w.position=p.id
GROUP BY p.id, p.position

虽然您可以使用单个SQL查询完成此操作,但使用PHP可能更直接

使用当前查询并将status添加到GROUP BY

SELECT p.id, p.position, w.status, count(*) FROM  tbl_positions as p
inner join tbl_workers as w on w.position=p.id
group by p.id, p.position, w.status

您将得到如下的结果集:

position    status  count
Driver        2       0
Lobby         2       0
Support       2       1
Constructor   2       0
Driver        3       0
Lobby         3       2
Support       3       0
Constructor   3       0

使用PHP逻辑判断2 = booked3 = placed