The CHARACTER_LENGTH (CHAR_LENGTH or LENGTH) function calculates the length of a value expression of any data type. If the result of the value expression is a character data type, the CHARACTER_LENGTH function returns the length, in characters, of the character string. (Remember that the length of a character can be one or more octets.) If the result of the value expression is NULL, the function returns a null value. You can use CHAR_ LENGTH or LENGTH as an alternative for CHARACTER_LENGTH.