Syntax:
QUOTE(str)

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. The QUOTE() function was added in MySQL 4.0.3.
