MYSQL按两个子查询分组，无需重复行

Question

How do I avoid repeating results in the following query?

Example table structure:

ord_order_number | ord_date   | ord_status | ord_from
----------------------------------------------------
          1      | 2017-01-01 |    2       | Admin Side 
          2      | 2017-02-02 |    3       | Client Side

There would be orders from all months leading up to 5 (Current month, May)

Here is the query:

SELECT t1.*, t2.*
    from 
        (select count(ord_order_number) as admin, ord_date
         FROM `order_summary`
         where ord_date > '2017-01-01 00:00:00' 
         and ord_from = 'Admin Side' 
         group by month(ord_date)
       ) t1,
       (select count(ord_order_number) as client, ord_date
        FROM `order_summary`
        where ord_date > '2017-01-01 00:00:00' 
        and ord_from = 'Client Side'
        group by month(ord_date)
       )t2

This will currently produce 25 4 columned rows.

The T1 alias will produce a count of each month starting from 2017-01 and ending and 2017-05. Each row would then repeat itself starting at 2017-01 etc...

while the t2 alias will repeat each month 5 times.

I would like for each month to only appear once.

Example results of current query:

(correct)admin |   ord_date  |  client |   ord_date (this column repeats each date 5 times)
       --------------------------------------------
           22  |  2017-01-01 |   77    | 2017-01-01
           32  |  2017-02-01 |   77    | 2017-01-01
           43  |  2017-03-01 |   77    | 2017-01-01

Here's an example of the expected results

admin |   ord_date  |  client |   ord_date
--------------------------------------------
  22  |  2017-01-01 |   77    | 2017-01-01
  32  |  2017-02-01 |   21    | 2017-02-01
  43  |  2017-03-01 |   100   | 2017-03-01

Answer 1

Move the condition in the select with CASE.You can add the ord_date again in the select but it looks weird to me.

SELECT count(CASE WHEN ord_from = 'Admin Side' THEN  ord_order_number END) as admin
     , count(CASE WHEN ord_from = 'Client Side' THEN  ord_order_number END) as client
     , ord_date
FROM `order_summary`
WHERE ord_date > '2017-01-01 00:00:00' 
GROUP BY month(ord_date)