LEN function [String]

Takes one argument as an input of type BINARY or STRING and returns the number of characters, as defined by the database's collation sequence, of a specified string expression, excluding trailing blanks. The result may differ from the string’s byte length for multi-byte character sets.

BINARY and VARBINARY are also allowed, in which case LEN() returns the number of bytes of the input.

LEN is an alias of LENGTH function

LEN ( string_expr )

The following example returns the value 3152:

select len(Photo) from Productswhere ID = 500

This function is the equivalent of CHAR_LENGTH ( string_expression ).

Any user can execute LEN.

ANSI SQL – Compliance level: Transact-SQL extension