Managing & Using MySQL, 2nd Edition

Comparison Operators

Comparison operators compare values and return 1 if the comparison is true and 0 otherwise. Except for the <==> operator, NULL values cause a comparison operator to evaluate to NULL.

<> or !=

Match rows if the two values are not equal.

<=

Match rows if the left value is less than or equal to the right value.

<

Match rows if the left value is less than the right value.

>=

Match rows if the left value is greater than or equal to the right value.

>

Match rows if the left value is greater than the right value.

value BETWEEN value1 AND value2

Match rows if value is between value1 and value2, or equal to one of them.

value IN ( value1,value2, ...)

Match rows if value is among the values listed.

value NOT IN ( value1, value2, ...)

Match rows if value is not among the values listed.

value1 LIKE value2

Compares value1 to value2 and matches the rows if they match. The righthand value can contain the wildcard '%', which matches any number of characters (including 0), and '_', which matches exactly one character. This is probably the single most used comparison in SQL. Its most common use is comparing a field value with a literal containing a wildcard (e.g., SELECT name FROM people WHERE name LIKE 'B%').

value1 NOT LIKE value2

Compares value1 to value2 and matches the rows if they differ. This is identical to NOT (value1 LIKE value2).

value1 REGEXP/RLIKE value2

Compares value1 to value2 using the extended regular expression syntax and matches the ...