Question

我具有以下表格结构

leads
-id
-fname
-lname


subcontractors
-id
-leads_id
-fname
-lname
-status

铅可以有许多subcontractors。 subcontractors.status告知分包商是处于活动状态还是已暂停

问题是我该如何选择带有计数列的销售线索，以告诉他们有多少个活动和暂停的子图标？

我现在有这个：

SELECT 
l.id, 
l.fname, 
l.lname, 
s.status 
FROM leads l 
INNER JOIN subcontractors s 
ON l.id = s.leads_id 
GROUP BY l.id ORDER BY l.id DESC;

我的目标是拥有这样的东西

id | fname | lname | active_subcon_count | suspended_subcon_count

Answer 1

您可以尝试将条件汇总函数COUNT与CASE WHEN一起使用

SELECT 
    l.id, 
    l.fname, 
    l.lname, 
    COUNT(CASE WHEN s.status = 'active' THEN 1 END) ,
    COUNT(CASE WHEN s.status = 'suspended' THEN 1 END) 
from leads l 
INNER JOIN subcontractors s 
ON l.id = s.leads_id 
GROUP BY l.id , l.fname, l.lname
ORDER BY l.id DESC;

或者mysql可以这样做SUM。

SELECT 
    l.id, 
    l.fname, 
    l.lname, 
    SUM(s.status = 'active') active_subcon_count ,
    SUM(s.status = 'suspended') suspended_subcon_count 
from leads l 
INNER JOIN subcontractors s 
ON l.id = s.leads_id 
GROUP BY l.id , l.fname, l.lname
ORDER BY l.id DESC;

MySQL列为一列

1 个答案: