IN¶

IN is used to test if an expression is contained in a list of values.

This is also known as set membership.

Syntax¶

expr [ NOT ] IN  ( value_expr [, ...] )

Arguments¶

Parameter	Description
`expr`	A general value expression or a literal to test.
`value_expr [, ...]`	A comma separated list of literal values of the same data type as `expr`

Returns¶

Returns TRUE when expr is contained in the set, or FALSE otherwise.

Notes¶

NULL is never equal to NULL, so to check if a value is NULL use IS NULL instead.
Using IN with more than 100 literal values can slow down query compilation. If your query relies on more than 100 values, consider using a lookup table and an inner join.

Examples¶

IN¶

farm=> SELECT name, num_eyes FROM cool_animals WHERE num_eyes IN (8, 10)
name           | num_eyes
---------------+---------
Spider         |        8
Horseshoe crab |       10

NOT IN¶

farm=> SELECT name, num_eyes FROM cool_animals WHERE num_eyes NOT IN (8, 10)
name           | num_eyes
---------------+---------
Box Jellyfish  |       24
Human          |        2
Fox            |        2
Possum         |        2