   expr REGEXP pat
   expr RLIKE pat

Performs a pattern match of a string expression expr against a pattern
pat.  The pattern can be an extended regular expression.  The syntax
for regular expressions is discussed in [Regexp].  Returns 1
if expr matches pat, otherwise returns 0.  If either
expr or pat is NULL, the result is NULL.
RLIKE is a synonym for REGEXP, provided for mSQL
compatibility.

The pattern need not be a literal string. For example, it can be specified
as a string expression or table column.

Note: Because MySQL uses the C escape syntax in strings (for example,
'\n' to represent newline), you must double any '\' that you
use in your REGEXP strings.

As of MySQL 3.23.4, REGEXP is not case sensitive for normal (not
binary) strings.
