In MariaDB, CHAR() is a built-in string function that returns characters based on their code values.

CHAR() accepts one or more integers. It then returns a string consisting of the characters given by the code values of those integers.

Syntax

The syntax goes like this:

CHAR(N,... [USING charset_name])

Where N,... is one or more values that CHAR() interprets as int values.

The optional USING argument can be used to specify the character set to use.

Example

Here’s a simple example to demonstrate:

SELECT CHAR(77);

Result:

+----------+
| CHAR(77) |
+----------+
| M        |
+----------+

Here I provided just one integer, and so CHAR() returned just one character. In this case, the integer 77 maps to the uppercase letter M.

Multiple Characters

We can provide multiple integers, separated by a comma, which will result in multiple characters being returned.

Example:

SELECT CHAR(77, 97, 114, 105, 97);

Result:

+----------------------------+
| CHAR(77, 97, 114, 105, 97) |
+----------------------------+
| Maria                      |
+----------------------------+

The USING Argument

We can use the optional USING argument to specify a character set to use.

Example:

SELECT CHAR(49833 USING utf8);

Result:

+------------------------+
| CHAR(49833 USING utf8) |
+------------------------+
| ©                      |
+------------------------+

Case Sensitivity

Uppercase letters have a different value to their lowercase equivalents. Therefore, a different integer is required for each.

Example:

SELECT 
    CHAR(72),
    CHAR(104);

Result:

+----------+-----------+
| CHAR(72) | CHAR(104) |
+----------+-----------+
| H        | h         |
+----------+-----------+

Null Values

null arguments are skipped.

Example:

SELECT CHAR(77, null, 77);

Result:

+--------------------+
| CHAR(77, null, 77) |
+--------------------+
| MM                 |
+--------------------+

If null is the only argument, then nothing is returned:

SELECT CHAR(null);

Result:

+------------+
| CHAR(null) |
+------------+
|            |
+------------+