MySQL查询选择计数在哪里分组

Question

I have this data:

| bid_id | created             | auction_id | user_id | bid_credits | bid_credits_free | bid_rating | balance | bidded_price | last_for_user | bid_ip       | bid_type |
+--------+---------------------+------------+---------+-------------+------------------+------------+---------+--------------+---------------+--------------+----------+
|    735 | 2013-10-11 10:02:58 |       9438 |   62323 |           1 |                0 |     0.0000 |  100333 |         0.86 | Y             | 72.28.166.61 | single   |
|    734 | 2013-10-11 10:02:56 |       9438 |   76201 |           1 |                1 |     0.0000 |    1115 |         0.85 | Y             | 72.28.166.61 | single   |
|    733 | 2013-10-11 10:02:55 |       9438 |   62323 |           1 |                0 |     0.0000 |  100334 |         0.84 | N             | 72.28.166.61 | single   |
|    732 | 2013-10-11 10:02:54 |       9438 |   76201 |           1 |                1 |     0.0000 |    1116 |         0.83 | N             | 72.28.166.61 | single   |
|    731 | 2013-10-11 10:02:52 |       9438 |   62323 |           1 |                0 |     0.0000 |  100335 |         0.82 | N             | 72.28.166.61 | single   |

I'm trying to get the number of "bid_credits" and "bid_credits_free" as SEPARATE VALUES...

So the query should return me:

| user_id | count(bid_credits) | count(bid_credits_free) |
+---------+--------------------+-------------------------+
|   62323 |                  3 |                       0 |
|   76201 |                  2 |                       2 |

The query that I am using is:

select user_id, count(bid_credits), count(bid_credits_free) from bids_history 
where auction_id = 9438 and user_id in (62323,76201) group by user_id;

but it's not counting the bids correctly... Any ideas?

Thanks

Answer 1

use a sum instead of count when grouping.. should work

I also reformatted so its easier to read :)

SELECT 
    user_id, 
    SUM(bid_credits), 
    SUM(bid_credits_free) 
FROM bids_history 
WHERE auction_id = 9438 AND user_id IN (62323,76201) 
GROUP BY user_id;

the reason why you want to use a sum instead of count is the count will just count the number of rows in a table, but not the contents / value of whats inside it. so when you group by an id like that you need to do a sum to see the actual addition of the contents. hope that helps explain things a bit :)

Answer 2

You're looking to SUM them, COUNT is just counting rows. Try this:

select user_id, sum(bid_credits), sum(bid_credits_free) from bids_history 
where auction_id = 9438 and user_id in (62323,76201) group by user_id;

Answer 3

Try this query :

Please use SUM instead of COUNT...

SELECT user_id, SUM(bid_credits) AS bid_credits, SUM(bid_credits_free) AS bid_credits_free FROM bids_history WHERE auction_id = 9438 AND user_id IN (62323,76201) GROUP BY user_id;

Answer 4

I think this may help you

select user_id, sum(bid_credits) AS bidCreditsCount, sum(bid_credits_free) AS bidCreditsFreeCount from bids_history 
where auction_id = 9438 and user_id in (62323,76201) group by user_id;