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Conditional Expression Functions

[ NOT ] IN

Tests whether its argument is or is not one of the members of an explicit list or the result of a subquery.

Note

In subquery form, IN is equivalent to = ANY and NOT IN is equivalent to <> ALL.

Syntax

To compare individual values:

<value> [ NOT ] IN ( <value_1> [ , <value_2> ...  ] )

To compare row constructors (parenthesized lists of values):

( <value_A> [, <value_B> ... ] ) [ NOT ] IN (  ( <value_1> [ , <value_2> ... ] )  [ , ( <value_3> [ , <value_4> ... ] )  ...  ]  )

To compare a value to the values returned by a subquery:

<value> [ NOT ] IN ( <subquery> )

Parameters

value

The value for which to search.

value_A, value_B

The elements of a row constructor for which to search.

Ensure that each value on the right of IN (e.g. (value3, value4)) has the same number of elements as the value on the left of IN (e.g. (value_A, value_B)).

value_#

A value to which value should be compared.

If the values to compare to are row constructors, then each value_# is an individual element of a row constructor.

subquery

A subquery that returns a list of values to which value can be compared.

Usage Notes

  • As in most contexts, NULL is not equal to NULL. If value is NULL, then the return value of the function is NULL, whether or not the list or subquery contains NULL.

    For example, the following returns NULL, not TRUE:

    SELECT NULL IN (1, 2, NULL);
    
  • Syntactically, IN is treated as an operator rather than a function. The example below shows the difference between using IN as an operator and calling f() as a function:

    SELECT
        f(a, b),
        x IN (y, z) ...
    

    You cannot use function syntax with IN. For example, you cannot rewrite the preceding example as:

    SELECT
        f(a, b),
        IN(x, (y, z)) ...
    
  • IN is also considered a subquery operator.

Collation Details

Arguments with collation specifications are currently not supported.

Examples

Using IN with Simple Literals

The following examples show how to use IN with simple literals:

SELECT
    CASE
        WHEN 1 IN (1, 2, 3)
        THEN 'true'
        ELSE 'false'
    END AS RESULT;
+--------+
| RESULT |
|--------|
| true   |
+--------+
SELECT
    CASE
        WHEN 'a' NOT IN (SELECT column1 FROM VALUES ('b'), ('c'), ('d'))
        THEN 'true'
        ELSE 'false'
    END AS RESULT;
+--------+
| RESULT |
|--------|
| true   |
+--------+

Using IN with a Table

This example shows how to use IN with a table:

CREATE TABLE MyTable (col_1 INTEGER, col_2 INTEGER, col_3 INTEGER);
INSERT INTO MyTable (col_1, col_2, col_3) VALUES
    (1, 1, 1),
    (1, 2, 3),
    (4, 5, NULL);
SELECT *
    FROM MYTABLE
    WHERE (col_1, col_2, col_3) IN ((1,2,3),(4,5,6));
+-------+-------+-------+
| COL_1 | COL_2 | COL_3 |
|-------+-------+-------|
|     1 |     2 |     3 |
+-------+-------+-------+

Remember that NULL != NULL. The following shows that “(4, 5, NULL)” does not match itself because NULL does not match itself:

SELECT *
    FROM MYTABLE
    WHERE (col_1, col_2, col_3) IN ((9, 8, 7), (4, 5, NULL));
+-------+-------+-------+
| COL_1 | COL_2 | COL_3 |
|-------+-------+-------|
+-------+-------+-------+

Using NOT IN

This is a simple example of using NOT IN:

SELECT *
    FROM MYTABLE
    WHERE (col_1, col_2, col_3) NOT IN ((1, 1, 1), (2, 2, 2));
+-------+-------+-------+
| COL_1 | COL_2 | COL_3 |
|-------+-------+-------|
|     1 |     2 |     3 |
|     4 |     5 |  NULL |
+-------+-------+-------+
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