Question

I wrote the query below, and it returns the data I need. However, I can’t help but think there’s a better way to write it. What I need is to find all the unique rows in Table1 that have prices greater than the price a specified vendor has in the categories to which the vendor belong. (In theory, there is no limit to the number of categories to which a vendor can belong).

• Table1 is a cross-reference table containing VendorID, Category, and price
• Table2 contains vendor information
• There is a category table that contains the category names.

…

SELECT DISTINCT Table2.name, Table2.city, Table2.state
FROM Table1 INNER JOIN Table2 ON Table1.VendorID = Table2.VendorID
WHERE Table1.Category IN (49,50,45)
    AND Table1.price > (SELECT price FROM Table1 WHERE VendorID = 69041 AND Category = 50)
    AND Table1.price > (SELECT price FROM Table1 WHERE VendorID = 69041 AND Category = 49)
    AND Table1.price > (SELECT price FROM Table1 WHERE VendorID = 69041 AND Category = 45)

Answer 1

You could use a Common Table Expression or a subquery to pull in all the data you need first and then join your tables to that “view”:

;WITH MaxPricePerCategory
AS
    (
    SELECT MAX(Price) AS [Price]
        -- You can remove category if you just need the maximum price
        , Category
    FROM Table1
    WHERE VendorID = 69041
    AND Table1.Category IN (49,50,45)
    GROUP BY Category
    )
SELECT DISTINCT Table2.name
    , Table2.city
    , Table2.state
FROM Table1 
JOIN Table2 
    ON Table1.VendorID = Table2.VendorID
JOIN MaxPricePerCategory MPPC
    ON Table1.Category = MPPC.Category
        AND Table1.price > MPPC.Price