MySQL - length() vs char_length()
LENGTH() returns the length of the string measured in bytes. CHAR_LENGTH() returns the length of the string measured in characters.
This is especially relevant for Unicode, in which most characters are encoded in two bytes. Or UTF-8, where the number of bytes varies. For example:
select length(_utf8 '€'), char_length(_utf8 '€')--> 3, 1As you can see the Euro sign occupies 3 bytes (it's encoded as 0xE282AC in UTF-8) even though it's only one character.