@STRNCMP
Use the @STRNCMP function to compare two strings based on a specific number of bytes. The string can be either the name of a string (character) column or a literal string that is enclosed within single quote marks. The comparison starts at the first byte in the string.
                  
@STRNCMP returns the following:
                  
- 
                        –1if the first string is less than the second.
- 
                        0if the strings are equal.
- 
                        1if the first string is greater than the second.
This function does not support NCHAR or NVARCHAR data types.
                  
Syntax
@STRNCMP (string1, string2, max_length)
Example
The following example compares the first two bytes of each string, as specified by a max_length of 2, and it returns 0 because both sets are the same.
                  
@STRNCMP ('JOHNSON', 'JONES', 2)