It’s likely that if you’ve performed a SELECT or UPDATE query in the recent past, you’ve made use of one or more of MySQL’s comparison operators in constraining your query’s output.

Comparison is an integral part of most SELECT queries, and MySQL comes with numerous functions for this; at last count, it had over 20 such operators and functions, ranging from well-known ones like = and LIKE to more esoteric ones like NOT IN and STRCMP(). (Article dated: February 9, 2007)

Read: Get more data comparison options in MySQL with operators you may not know