I have 4 tables that I need to connect in order to get the reports that I need. But I’m confused on how to write the query. Below are the sample of the tables:
Client Table
JavaScript
x
client_id | client_name | con_id
----------:|:-------------:|:-------
1 | ABC | 1
2 | DEF | 1
3 | GHI | 2
Consultant
JavaScript
con_id | con_name
-------:|:---------
1 | Ani
2 | Robby
Perm
JavaScript
pid | client_id | date
----:|:-----------:|:-----------
1 | 1 | 2014-08-09
2 | 1 | 2014-03-02
3 | 2 | 2014-03-02
Temp
JavaScript
tid | client_id | date
----:|:-----------:|:-----------
1 | 2 | 2013-02-09
2 | 3 | 2011-03-02
3 | 3 | 2012-04-02
The end result of the report that I want to show is something like this:
JavaScript
client_id | client_name | perm(COUNT) | temp(COUNT) | con_name
----------:|:-------------:|:-------------:|:-------------:|:---------
1 | ABC | 2 | 0 | Ani
2 | DEF | 1 | 1 | Ani
3 | GHI | 0 | 2 | Robby
I’m trying to use the LEFT OUTER JOIN
, but I don’t get the result that I want. Can anyone help me to figure out the query?
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Answer
this is a simple outer join query with count and group by,just join your client
table with the related ones and count only the distinct associations
JavaScript
select
c.client_id,
c.client_name,
count(distinct p.pid) perm_count,
count(distinct t.tid) temp_count,
cn.con_name
from client c
left join Consultant cn on(c.con_id = cn.con_id)
left join Perm p on(c.client_id = p.client_id)
left join `Temp` t on(c.client_id = t.client_id)
group by c.client_id