Group sum from two tables according to date in MySQL

Question

Hi,

I have two different tables, lead and click. I would like to query MySQL to get the sum of the commissions generated by clicks and leads ordered by date.

Lead

id|date|commission

Click

id|date|commission

(Both have other fields, but they aren't important for this question.)

So if I had: Lead:

1|2009-06-01|400
2|2009-06-01|300
3|2009-06-03|350

Click:

1|2009-06-01|1
2|2009-06-03|2
3|2009-06-03|1

I would like to create a query that gives me (and if possible also gets date where no lead or click has been generated): date|commission click|commission lead|total commission

So the result from the query with the data from the tables above would be:

2009-06-01|1|700|701
2009-06-02|0|0|0
2009-06-02|3|350|353

(The date is actually datetime in the real database.)

I guess I have to combine:

SELECT count(*) as number_clicks, sum(click.commission) as sum_clicks,
 date(click.time) as click_date from click group by click_date order by click_date

With:

SELECT count(*)as number_leads, sum(lead.commission) as sum_leads,
 date(lead.time) as lead_date from lead group by lead_date order by lead_date

But I can not get them to work together.

Answer 1

This doesn't get dates with zeroes, for that you'll either need a dates table or a stored procedure to loop through dates. One way to do it is a subselect from a union query (untested):

SELECT commission_date, SUM(click_commission), SUM(lead_commission), SUM(total_commission)
FROM (SELECT DATE(click.time) AS commission_date, click.commission AS click_commission,
             0 AS lead_commission, click.commission AS total_commission
      FROM click
      UNION ALL
      SELECT DATE(lead.time) AS commission_date, 0 AS click_commission,
             lead.commission AS lead_commission, lead.commission AS total_commission
      FROM lead) AS foo
GROUP BY commission_date
ORDER BY commission_date