SQL - Display the minimum value of an average price - sql

Question

My database contains a list of products and finishes. I have been able to successfully average the price of each finish option, but I only want to display the lowest priced option.
Here is a sample of my data.
Table 1 - product_t
ProductID ProductLineID ProductDescription ProductFinish ProductStandardPrice ProductOnHand
1 1 "Cherry End Table" Cherry 175.00 0
2 1 "Birch Coffee Tables" Birch 200.00 0
3 1 "Oak Computer Desk" Oak 750.00 0
4 1 "Entertainment Center" Cherry 1650.00 0
This query results in a list of each available product finish and the average price of an item that has the finish.
SELECT ProductFinish, AVG(ProductStandardPrice) as AveragePrice
FROM product_t
WHERE ProductFinish IS NOT NULL
GROUP BY ProductFinish;
However, I only want to display the lowest price that results from this query. I attempted this query, but it will not execute.
SELECT ProductFinish, MIN (AVG(ProductStandardPrice)) as AveragePrice
FROM product_t
WHERE ProductFinish IS NOT NULL
GROUP BY ProductFinish;
Thanks in advance for any help. It is much appreciated.

Answer 1

A typical way to get the lowest value is to use order by and some sort of limit on the number of rows. In ANSI standard SQL, this would be:
SELECT ProductFinish, AVG(ProductStandardPrice) as AveragePrice
FROM product_t
WHERE ProductFinish IS NOT NULL
GROUP BY ProductFinish;
ORDER BY AveragePrice ASC
FETCH FIRST 1 ROW ONLY;
Note that some databases using LIMIT 1 or TOP 1 instead of FETCH FIRST 1 ROW ONLY. Also, this version only fetches one record with the lowest price. If there are duplicate minimums, an arbitrary value is chosen.