Syntax
CHAR_LENGTH(str)
Purpose
CHAR_LENGTH() returns the number of characters in the str string.
A multi-byte character is counted as one character. For example, if you enter five two-byte characters, the LENGTH() function returns 10, while the CHAR_LENGTH() function returns 5.
Examples
obclient> SELECT CHAR_LENGTH('CN'), LENGTH('CN'),CHAR_LENGTH('hello');
+-----------------------+------------------+----------------------+
| CHAR_LENGTH('CN') | LENGTH('CN') | CHAR_LENGTH('hello') |
+-----------------------+------------------+----------------------+
| 2 | 6 | 5 |
+-----------------------+------------------+----------------------+
1 row in set