How the RTRIM() Function Works in MySQL

In MySQL, the RTRIM() function trims whitespace from the right-hand side of a string.

Syntax

The syntax goes like this:

RTRIM(str)

Where str is the string to trim.

Example

Here’s a basic example of removing whitespace from the end of a string:

SELECT RTRIM('Rattlesnake ') AS Trimmed;

Result:

+-------------+
| Trimmed     |
+-------------+
| Rattlesnake |
+-------------+

The trailing space is removed.

To demonstrate the effect better, here’s what it looks like when compared to the untrimmed string:

SELECT 
  'Rattlesnake ' AS Untrimmed,
  RTRIM('Rattlesnake ') AS Trimmed;

Result:

+--------------+-------------+
| Untrimmed    | Trimmed     |
+--------------+-------------+
| Rattlesnake  | Rattlesnake |
+--------------+-------------+

If you look closely, you’ll see that the first one has extra space at the end and the second one doesn’t. This is even more clearly demonstrated in the next example.

Multiple Spaces

If you have multiple trailing spaces, all of them are trimmed:

SELECT 
  'Rattlesnake        ' AS Untrimmed,
  RTRIM('Rattlesnake        ') AS Trimmed;

Result:

+---------------------+-------------+
| Untrimmed           | Trimmed     |
+---------------------+-------------+
| Rattlesnake         | Rattlesnake |
+---------------------+-------------+

Other Spaces

This function only trims trailing space. Any other space is left alone:

SELECT 
  '     Crotalus triseriatus     ' AS Untrimmed,
  RTRIM('     Crotalus triseriatus     ') AS Trimmed;

Result:

+--------------------------------+---------------------------+
| Untrimmed                      | Trimmed                   |
+--------------------------------+---------------------------+
|      Crotalus triseriatus      |      Crotalus triseriatus |
+--------------------------------+---------------------------+

In this example, space between each word is left intact, and leading space is also left intact on both strings. Only the the second string has its trailing space trimmed.