In MariaDB, REVERSE()
is a built-in string function that returns a string with the characters in reverse order.
The function accepts one argument: the string to reverse.
Syntax
The syntax goes like this:
REVERSE(str)
Where str
is the string to reverse.
Example
Here’s a basic example:
SELECT REVERSE('abc');
Result:
+----------------+ | REVERSE('abc') | +----------------+ | cba | +----------------+
Database Example
Here’s an example that reverses the data returned from a database column:
SELECT
PetName,
REVERSE(PetName)
FROM Pets;
Result:
+---------+------------------+ | PetName | REVERSE(PetName) | +---------+------------------+ | Fluffy | yffulF | | Fetch | hcteF | | Scratch | hctarcS | | Wag | gaW | | Tweet | teewT | | Fluffy | yffulF | | Bark | kraB | | Meow | woeM | +---------+------------------+
Empty String
Passing an empty string returns an empty string:
SELECT REVERSE('');
Result:
+-------------+ | REVERSE('') | +-------------+ | | +-------------+
Null Arguments
Providing null
results in null
:
SELECT REVERSE(null);
Result:
+---------------+ | REVERSE(null) | +---------------+ | NULL | +---------------+
Missing Argument
Calling REVERSE()
with the wrong number of arguments, or without passing any arguments results in an error:
SELECT REVERSE();
Result:
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ')' at line 1