GROUP_CONCAT ORDER BY

Ho un tavolo come:

+-----------+-------+------------+ | client_id | views | percentage | +-----------+-------+------------+ | 1 | 6 | 20 | | 1 | 4 | 55 | | 1 | 9 | 56 | | 1 | 2 | 67 | | 1 | 7 | 80 | | 1 | 5 | 66 | | 1 | 3 | 33 | | 1 | 8 | 34 | | 1 | 1 | 52 | 

Ho provato group_concat :

 SELECT li.client_id, group_concat(li.views) AS views, group_concat(li.percentage) FROM li GROUP BY client_id; +-----------+-------------------+-----------------------------+ | client_id | views | group_concat(li.percentage) | +-----------+-------------------+-----------------------------+ | 1 | 6,4,9,2,7,5,3,8,1 | 20,55,56,67,80,66,33,34,52 | +-----------+-------------------+-----------------------------+ 

Ma voglio ottenere le viste in ordine, come:

 +-----------+-------------------+----------------------------+ | client_id | views | percentage | +-----------+-------------------+----------------------------+ | 1 | 1,2,3,4,5,6,7,8,9 | 52,67,33,55,66,20,80,34,56 | +-----------+-------------------+----------------------------+ 

Puoi utilizzare ORDER BY all’interno della funzione GROUP_CONCAT in questo modo:

 SELECT li.client_id, group_concat(li.percentage ORDER BY li.views ASC) AS views, group_concat(li.percentage ORDER BY li.percentage ASC) FROM li GROUP BY client_id 

Il group_concat supporta la propria clausola order by

http://mahmudahsan.wordpress.com/2008/08/27/mysql-the-group_concat-function/

Quindi dovresti essere in grado di scrivere:

 SELECT li.clientid, group_concat(li.views order by views) AS views, group_concat(li.percentage order by percentage) FROM table_views GROUP BY client_id 

Provare

 SELECT li.clientid, group_concat(li.views ORDER BY li.views) AS views, group_concat(li.percentage ORDER BY li.percentage) FROM table_views li GROUP BY client_id 

http://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html#function%5Fgroup-concat

In IMPALA, non avere ordine nel GROUP_CONCAT può essere problematico, a Coders’Co. abbiamo una sorta di soluzione alternativa per questo (ne abbiamo bisogno per Rax / Impala). Se hai bisogno del risultato GROUP_CONCAT con una clausola ORDER BY in IMPALA, dai un’occhiata a questo post del blog: http://raxdb.com/blog/sorting-by-regex/