How the LCASE() Function Works in MySQL

In MySQL, the LCASE() function is a synonym for LOWER(). In other words, you can use either of these functions to do the same thing.

Specifically, both functions convert uppercase characters to lowercase, according to the current character set mapping (the default mapping is utf8mb4).

Syntax

The syntax goes like this:

LCASE(str)

Where str is the string to be changed to lowercase.

Example

Here’s an example:

SELECT 
  LCASE('CAT'),
  LOWER('CAT');

Result:

+--------------+--------------+
| LCASE('CAT') | LOWER('CAT') |
+--------------+--------------+
| cat          | cat          |
+--------------+--------------+

Binary Strings

These functions don’t work on binary strings. If you need to use them on a binary string, you’ll need to convert the string to a nonbinary string first. Here’s an example:

SET @str = BINARY 'Cat';
SELECT 
  LCASE(@str) AS 'Binary', 
  LCASE(CONVERT(@str USING utf8mb4)) AS 'Nonbinary';

Result:

+--------+-----------+
| Binary | Nonbinary |
+--------+-----------+
| Cat    | cat       |
+--------+-----------+

Using LCASE() in Views

One thing to be aware of is that, when the LCASE() function is used within a view, it is rewritten and stored as LOWER().