Comments on: GROUP_CONCAT useful GROUP BY extension

By: Murz

Murz — Thu, 25 Sep 2008 05:52:07 +0000

A litte problem I had with the group_concat function was when selecting integers only I was getting a blob instead of a string to solve this I used a CONCAT:

SELECT CONCAT(GROUP_CONCAT(myInt),”) myInts FROM aTable;

By: Kestas

Kestas — Thu, 03 Jul 2008 09:30:55 +0000

Has MySQL rollup, cubes or grouping sets like Oracle?

By: Eduardo

Eduardo — Mon, 30 Jun 2008 14:48:11 +0000

Hi, is it possible to use some kind of argument in group_concat that allows it to group 2 by 2? p.ex:
SELECT id,client_id FROM services WHERE id = 3;
+—-+———–+
| id | client_id |
+—-+———–+
| 3 | 5 |
| 3 | 6 |
| 3 | 7 |
| 3 | 8 |
| 3 | 9 |
| 3 | 10 |
| 3 | 11 |
+—-+———–+

SELECT id,GROUP_CONCAT(client_id,2) FROM services WHERE id = 3 GROUP BY id;
+—-+————————-+
| id | GROUP_CONCAT(client_id) |
+—-+————————-+
| 3 | 5,6 |
+—-+————————-+
| 3 | 6,7 |
+—-+————————-+
| 3 | 7,8 |
+—-+————————-+
| 3 | 8,9 |
+—-+————————-+
| 3 | 9,10 |
+—-+————————-+
| 3 | 10,11 |
+—-+————————-+
Thanks!

By: DHIRAJ

DHIRAJ — Thu, 12 Jun 2008 07:50:35 +0000

where i can get my.cnf file or
how to set global

By: Vadim

Vadim — Wed, 11 Jun 2008 17:16:05 +0000

group_concat_max_len=4096 in my.cnf
or SET GLOBAL group_concat_max_len=4096

By: DHIRAJ

DHIRAJ — Wed, 11 Jun 2008 03:52:34 +0000

how to extent the limit of group concat > 1024

By: Vadim

Vadim — Fri, 06 Jun 2008 22:43:48 +0000

There is group_concat_max_len server variable, which by default is 1024

By: DHIRAJ

DHIRAJ — Fri, 06 Jun 2008 06:26:43 +0000

GROUP_CONCAT IS VERY NICE, BUT THERE IS A LIMIT UPTO 1024, CAN WE INCREASE THE LIMIT? IF YES PLEASE

By: Rizwan

Rizwan — Thu, 15 May 2008 07:28:34 +0000

I have created a table (with only 2 fields) with the following query

1.CREATE TABLE `users` (
2.`id` INT NOT NULL AUTO_INCREMENT PRIMARY KEY ,
3.`name` VARCHAR( 20 ) NOT NULL
4.) ENGINE = MYISAM ;”

There are 20,000 users in this table with ids from 1 to 20,000
On executing the following query
Code: ( text )

1. select group_concat(id separator ‘,’) from users

returns only 283 ids separated with ‘,’

By: Chris

Chris — Wed, 30 Jan 2008 18:19:04 +0000

My sincere thanks to - 6. paul carey for publishing this fix - you saved my sanity.