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Asked: 2026-05-26T22:54:23+00:00

I’m trying to build an sql query with no success. As I’m a newbie

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I’m trying to build an sql query with no success. As I’m a newbie i hope to find your help.

Scenery: a store is organizing an award among its customers. Here is the database they have:

__________________________________________________________________
id  |    name     |   date     |   time   |   item   |  section  |
__________________________________________________________________

01  |  J. Smith   | 2011-10-30 | 10:12:56 |  shoes   |   sport   |
02  |  J. Smith   | 2011-10-27 | 11:14:19 |  T-shirt |   sport   |
03  |  M. Douglas | 2011-11-01 | 04:00:42 | keyboard | computer  |
04  |  R. Obrian  | 2010-12-31 | 11:33:57 |  webcam  | computer  |
05  |  M. Douglas | 2011-01-07 | 12:42:00 |  webcam  | computer  |
06  |  J. Smith   | 2011-02-05 | 02:30:51 |  T-shirt |   sport   |
07  |  J. Smith   | 2011-05-12 | 06:55:14 |  bike    |   sport   |
08  |  J. Smith   | 2011-03-15 | 09:59:22 |  shoes   |   sport   |
09  |  J. Smith   | 2011-09-09 | 08:10:36 |  webcam  | computer  |
10  |  J. Smith   | 2011-06-09 | 10:00:38 |microphone| computer  |

I want to make a top 10 list of customers for each section, with the following criteria: the best buyer is who bought the major number of DIFFERENT items. In case of same results (same number of different items bought) among customers, the best buyer is who 1st (date & time) bought all his items.

I’d like to have, for example, the following top 10 results table:

                          SPORT
 ____________________________________________________________ 
 |  name   |   items bought (different)  |     Date & Time   |
 ____________________________________________________________ 
 | XXXYYY  |             16              | 2011-10-05  @07:15| 
 | ZZZZTT  |             16              | 2011-10-05  @08:10| 
 | QQHAIJ  |             16              | 2011-10-06  @10:35| 
 | TTTSFT  |             15              | 2011-11-03  @12:22|
 | LIUREN  |             14              | 2011-11-14  @16:10|
 | ODIRNU  |             9               | 2011-07-03  @14:18|
 | OIXUED  |             8               | 2011-11-20  @03:03|
 | SUHDKO  |             7               | 2011-02-02  @22:51|
 | TNODJH  |             7               | 2011-06-10  @12:55|
 | ENOSJR  |             6               | 2011-04-04  @11:39|
 _____________________________________________________________

The queries must be different for each section, id est i must have a different string (and table of results) for SPORT, COMPUTER…et cetera.

Who can help me? Thanks in advance!

Bob.

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1 Answer

  1. Editorial Team

    Early first item purchaser wins

    SELECT name,
    COUNT(DISTINCT item) AS items, 
    MIN(ADDTIME(`date`,`time`)) AS `datetime`
FROM purchase
WHERE section = 'computer'
GROUP BY name
ORDER BY items DESC, `datetime` ASC
LIMIT 0,10

    Example table result:

    |- name       -|- items -|- datetime            -|
|- M. Douglas -|- 2     -|- 2011-01-07 12:42:00 -|
|- J. Smith   -|- 2     -|- 2011-06-09 10:00:38 -|
|- R. Obrian  -|- 1     -|- 2010-12-31 11:33:57 -|

    Early last item purchaser wins

    SELECT name,
    COUNT(DISTINCT item) AS items, 
    MAX(ADDTIME(`date`,`time`)) AS `datetime`
FROM purchase
WHERE section = 'computer'
GROUP BY name
ORDER BY items DESC, `datetime` ASC
LIMIT 0,10

    Example table result:

    |- name       -|- items -|- datetime            -|
|- J. Smith   -|- 2     -|- 2011-09-09 08:10:36 -|
|- M. Douglas -|- 2     -|- 2011-11-01 04:00:42 -|
|- R. Obrian  -|- 1     -|- 2010-12-31 11:33:57 -|
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