Syntax
LENGTH(str)
Purpose
Returns the length of str in bytes.
Each multibyte character is counted as multiple characters. For example, if you input five 2-byte characters, CHAR_LENGTH() returns 5, and LENGTH() returns 10.
Examples
obclient> SELECT LENGTH('China'), LENGTH('hello');
+------------------+-----------------+
| LENGTH('China') | LENGTH('hello') |
+------------------+-----------------+
| 6 | 5 |
+------------------+-----------------+
1 row in set