GROUP_CONCAT ORDER BY
MysqlSql Order-ByGroup ConcatMysql Problem Overview
I've a table like:
+-----------+-------+------------+
| 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 |
I tried 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 |
+-----------+-------------------+-----------------------------+
But I want to get the views in order, like:
+-----------+-------------------+----------------------------+
| client_id | views | percentage |
+-----------+-------------------+----------------------------+
| 1 | 1,2,3,4,5,6,7,8,9 | 52,67,33,55,66,20,80,34,56 |
+-----------+-------------------+----------------------------+
Mysql Solutions
Solution 1 - Mysql
You can use ORDER BY inside the GROUP_CONCAT function in this way:
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
Solution 2 - Mysql
The group_concat supports its own order by clause
http://mahmudahsan.wordpress.com/2008/08/27/mysql-the-group_concat-function/
So you should be able to write:
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
Solution 3 - Mysql
Try
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
Solution 4 - Mysql
You can use SEPARATOR and ORDER BY inside the GROUP_CONCAT function in this way:
SELECT li.client_id, group_concat(li.percentage ORDER BY li.views ASC SEPARATOR ',')
AS views, group_concat(li.percentage ORDER BY li.percentage ASC SEPARATOR ',') FROM li
GROUP BY client_id;
Solution 5 - Mysql
In IMPALA, not having order in the GROUP_CONCAT can be problematic, over at Coders'Co. we have some sort of a workaround for that (we need it for Rax/Impala). If you need the GROUP_CONCAT result with an ORDER BY clause in IMPALA, take a look at this blog post: http://raxdb.com/blog/sorting-by-regex/