Oracle SQL - AVG function invalid identifier

Question

and good afternoon. Happy to post I haven't needed to post any questions in a bit and have instead started answering. Woo :)

Anyway, my problem here is that I am trying to write a subquery that pulls my vendor, their part, and how much their part is. The vendor may supply the part many times, so I want to AVERAGE the price of the part. Later, I am looking to see about any problem notices against those parts. However, I can't reference the field that I am averaging later on. What do I do?

The SQL looks as follows and is in ORACLE syntax:

WITH
PartVendor AS
(
SELECT PARTNAME, PARTNUM, AVG(PARTPRICE), VENDNAME, VENDNUM
FROM PARTBL
    INNER JOIN VENDTBL ON VENDNUM = PARTVENDNUM
GROUP BY PARTNAME, PARTNUM, VENDNAME, VENDNUM
),

PartProbs AS
(
SELECT PartVendor.*, PROBNUM, PROBDESC
FROM PartVendor
    INNER JOIN PROBTBL ON PARTNUM = PROBPARTNUM
)

SELECT *
FROM PartProbs

Later on, I will do more. But I keep getting an error on PARTPRICE telling me that it is an invalid identifier. Can anybody help?

Answer 1

You should name all columns in the CTE:

WITH PartVendor AS (
      SELECT PARTNAME, PARTNUM, AVG(PARTPRICE) as AVG_PARTPRICE, VENDNAME, VENDNUM
      FROM PARTBL INNER JOIN
           VENDTBL ON VENDNUM = PARTVENDNUM
      GROUP BY PARTNAME, PARTNUM, VENDNAME, VENDNUM
     ),
     . . .