The SQL Server CONCAT_WS() function concatenates two or more strings into one string with a separator. CONCAT_WS() means concatenate with separator.
The following shows the syntax of the CONCAT_WS() function:
CONCAT_WS(separator,input_string1,input_string2,[...input_stringN]);
SELECT
first_name,
last_name,
CONCAT_WS(', ', last_name, first_name) full_name
FROM
sales.customers
ORDER BY
first_name,
last_name;
The following picture shows the partial output:
