Trailing white space characters are included in the length returned.
The return value of a NULL string is NULL.
If the string is in a multibyte character set, the value returned by the CHAR_LENGTH function may differ from the number of
bytes returned by the BYTE_LENGTH function.
You can use the CHAR_LENGTH function and the LENGTH function interchangeably for CHAR, VARCHAR, and LONG VARCHAR data types.
However, you must use the LENGTH function for BINARY and bit array data types.