How to use GROUP BY to concatenate strings in MySQL?

Question

Basically, the question is how to get from this:

id    string

1          A

1          B

2          C

to this:

id    string

1          A B

2          C

Answer 1

Try this code:

SELECT id, GROUP_CONCAT(string SEPARATOR ' ') FROM table GROUP BY id;

You can refer to this link http://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html#function_group-concat

GROUPCONCAT: This function returns a string result with the concatenated non-NULL values from the group. This returns NULL if there are no non-NULL values.