Function

LENGTHB is a function in SQL that returns the byte length of a string argument. Unlike the CHAR_LENGTH or CHARACTER_LENGTH functions, LENGTHB calculates the number of bytes rather than the number of characters, which is particularly important when dealing with multi-byte character sets (such as UTF-8).

Syntax

LENGTHB(string)

Parameter Description

• string: The string expression whose byte length is to be calculated.

Return Result

This function returns an integer representing the total number of bytes in the input string. For NULL input, the return value is also NULL.

Example

Example 1: Basic Usage

SELECT LENGTHB('Hello, World!');

This will return 13

Example 2: Handling NULL Values

SELECT LENGTHB(NULL);

This will return NULL because the input parameter is NULL.

Example 3: Chinese Characters

SELECT LENGTHB('中文')
union all
SELECT CHARACTER_LENGTH('中文');
+---------------+
| LENGTHB('中文') |
+---------------+
| 3             |
| 6             |
+---------------+