Question

i have a 3 Tables:

1 TableTraders
trader_id|Domain|
---------------------
1|google.com
2|yahoo.com

2 Table Counter_in

counter_time    counter_ip  counter_domain_id
    111111  222222  1
    111111  222224  2
    111111  222225  3
    111111  222232  2
    111111  222221  3
    111111  222223  4
    1111311     22223422    5



 3 Table Out Counter
counter_time    counter_ip  counter_domain_id
    111111  222222  1
    111111  222222  2
    111111  222222  3
    111111  222226  2
    111111  222221  3
    111111  222222  4
1309351485  2130708581  5
    1309351485  2130708581  4
    1309710116  2130706433  4
    1309351485  2130708581  1
1309710274  2130706433  1

Ok what i want todo is join the tables 1 , 2 , 3 and group them together, and count them.

trader_id|DOMAIN|IN|OUT
--------------------------
1|google.com|3|1
2|yahoo.com|1|2

I tried many things, but i get always wrong results. How do i join right the queries that i get results i want

*EDIT

The query attempted:

SELECT traders.trader_id, traders.domain, COUNT( counter_in.counter_domain_id ) AS today_in, COUNT( counter_out.counter_domain_id ) AS today_out
FROM traders
JOIN counter_in ON traders.trader_id = counter_in.counter_domain_id
JOIN counter_out ON traders.trader_id = counter_out.counter_domain_id
GROUP BY traders.trader_id, traders.domain
LIMIT 0 , 30

Results:

trader_id   domain  today_in    today_out
1   bing.com    3   3
2   google.com  4   4
3   yahoo.com   4   4
4   msn.com     3   3
5   yandex.com  1   1

Answer 1

It appears the other answer may be giving you some sort of Cartesian result thus duplicating results. Take your traders and join to distinct sub-query counts from respective in / out tables.

SELECT
      TT.trader_id,
      TT.Domain,
      TIN.InCount,
      TOUT.OutCount
   FROM 
      TableTraders TT

         LEFT Join ( select Trader_ID, count(*) as InCount
                   from TableIn
                   group by Trader_ID ) TIN
            on TT.Trader_ID = TIN.Trader_ID

         LEFT Join ( select Trader_ID, count(*) as InCount
                   from TableOut
                   group by Trader_ID ) TOUT
            on TT.Trader_ID = TOUT.Trader_ID

If you want it by DISTINCT IP address per in/out, just change

COUNT(*) 
to
COUNT( Distinct IP )