While working on a project I was required to display the data fetched from a column in form of comma separated values. With couple of Google searches I was able able to land on a solution.
You can easily perform this task using MySQL’s GROUP_CONCAT function.
Let’s assume you have a books table and you are using following query to fetch all book ids from database where author’s id is 4.
SELECT id FROM `books` WHERE author_id = 4
The above query will produce following result.
id 1 2 5 9 12 15 18 20
And our desired output is as follows.
In order to produce the above output you can user following query.
SELECT GROUP_CONCAT(id) FROM `books` WHERE author_id = 4 GROUP BY author_id
This function concatenates multiple strings from a group into a single string.
For more information visit: http://dev.mysql.com/doc/refman/5.7/en/group-by-functions.html#function_group-concat