Currently only supports == and !=, should add these few in
(In ) Fixes #2188 adding < <= >= > !@ (does not contain) =@ (contains) operators, will update doc now
For LIKE and NOT LIKE, % and _ in the $value should be escaped.
(In ) Refs #2188 Escaping special LIKe characters - thanks for the code review!
(In ) Refs #2188 forgot to check in tests