AS
You can use an AS clause in a SELECT statement to name or rename a result column in a query. The name must not be qualified and does not have to be unique.
The following example shows the use of an AS clause in a query submitted in Db2® for z/OS®:
SELECT NAME, SALARY*0.05 AS "RAISE"
FROM Q.STAFF
If the AS clause is not specified and the result column is derived from a column name, the result column name is the unqualified name of that column.