Syntax
------

QUOTE(str)

Description
-----------

Quotes a string to produce a result that can be used as a properly escaped
data value in an SQL statement. The string is returned enclosed by single
quotes and with each instance of single quote ("'"), backslash ("\"), ASCII
NUL, and Control-Z preceded by a backslash. If the argument is NULL, the
return value is the word "NULL" without enclosing single quotes.

Examples
--------

SELECT QUOTE("Don't!");
+-----------------+
| QUOTE("Don't!") |
+-----------------+
| 'Don\'t!'       |
+-----------------+

SELECT QUOTE(NULL); 
+-------------+
| QUOTE(NULL) |
+-------------+
| NULL        |
+-------------+

URL: https://mariadb.com/kb/en/quote/