String concatenation with MySQL - Part 2

Posted December 16th, 2009 in MySql

A few months ago I posted about string concatenation with MySQL using the CONCAT function and in this follow up post look at the CONCAT_WS function which glues the fields together with the specified string. CONCAT_WS means CONCATenate With Separator i.e. join the fields together with a specified separator string.

Example data

The example table used in this post is called "products" and contains the following data, which is the same as in the original post:

+------------+------+--------------------+--------+
| product_id | name | description        | price  |
+------------+------+--------------------+--------+
|          1 | Foo  | Blah blah foo blah |  55.00 |
|          2 | Bar  | Blah blah bar blah | 102.00 |
|          3 | Baz  | Blah blah baz blah |  87.50 |
|          4 | Bat  | Blah blah bat blah |  42.00 |
+------------+------+--------------------+--------+

Using concat_ws to concatenate fields and strings

CONCAT_WS takes multiple arguments, the first being the string that glues the rest of the fields together. In my original post I joined the strings together with a hyphen surrounded by spaces with CONCAT ("SELECT CONCAT(name, ' - ', description) FROM products;") and this can be done instead with CONCAT_WS like so:

SELECT CONCAT_WS(' - ', name, description) FROM products;

The resulting data would look like this:

+-------------------------------------+
| CONCAT_WS(' - ', name, description) |
+-------------------------------------+
| Foo - Blah blah foo blah            |
| Bar - Blah blah bar blah            |
| Baz - Blah blah baz blah            |
| Bat - Blah blah bat blah            |
+-------------------------------------+

This can be a lot simpler to join multiple fields than using CONCAT if you are wanting to concatenate more than two fields.