MySQL Pocket Reference

Operators

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69

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 rows if the two val-

ues match. The righthand value can contain full Unix

regular expression wildcards and constructs (e.g.,

SELECT

name FROM people WHERE name RLIKE

'^B.*').

value1 NOT REGEXP value2

Compares value1 to value2 using the extended regular

expression syntax and matches the rows if they differ.

This is identical to

NOT (value1 REXEXP value2).

Logical Operators

Logical operators check the truth value of one or more

expressions. In SQL terms, a logical operator checks whether

its operands are 0, nonzero, or

NULL. A 0 value means false,

nonzero means true, and

NULL means no value.

NOT or !

Performs a logical not (returns “1” if the value is 0, NULL if

it is

NULL, otherwise “0”).

OR or ||

Performs a logical or (returns “1” if any of the arguments

are nonzero and non-

NULL, NULL if any are NULL; other-

wise, returns “0”).

XOR

Performs a logical exclusive or (returns “1” if one and

only on argument is nonzero and non-

NULL, NULL if any

are

NULL; otherwise. returns “0”).

AND or &&

Performs a logical and (returns “0” if any of the argu-

ments are 0,

NULL if any are NULL; otherwise, returns “1”).