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This page is part of MariaDB's Documentation.
The parent of this page is: SQL Operators for MariaDB Xpand
Topics on this page:
Overview
Equality without special treatment for NULL.
USAGE
value1 <=> value2
Value Name | Description |
|---|---|
| The two values to compare |
DETAILS
The <=> operator compares two values, returning 1 (true) if both values are equivalent, otherwise 0.
If at least one value is a number, a numeric comparison is performed. Thus, a string value is converted into a number when paired with a numeric value.
When both values are strings, the comparison takes into account the current sort order, which might treat uppercase and lowercase letters as equivalent.
A NULL value is not treated specially, so it compares equal to another NULL and unequal to everything else.
EXAMPLES
SELECT 42 <=> 42, 1 <=> 0, NULL <=> NULL;
+-----------+---------+---------------+
| 42 <=> 42 | 1 <=> 0 | NULL <=> NULL |
+-----------+---------+---------------+
| 1 | 0 | 1 |
+-----------+---------+---------------+
SELECT 99 <=> 123,
PI() <=> 3.141592653589793 AS pi_eq;
+------------+-------+
| 99 <=> 123 | pi_eq |
+------------+-------+
| 0 | 1 |
+------------+-------+
-- Disable strict mode or the comparison might throw an error
SET sql_mode = '';
SELECT 99 <=> '99a', 'abc' <=> 0;
+--------------+-------------+
| 99 <=> '99a' | 'abc' <=> 0 |
+--------------+-------------+
| 1 | 1 |
+--------------+-------------+