   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. 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.
