Question

I have following sql syntax. This works fine but I was wondering if there is a way to write this syntax simpler since MAX(ra0.DescPriority) uses same table join.

SELECT DISTINCT Items_1.ImageID, Items_1.SubcategoryID2, Items_1.AddDate,
                                 (SELECT        MAX(ra0.DescPriority) AS Expr1
                                   FROM            Items INNER JOIN
                                                             Attribs AS ra0 ON Items.ImageID = ra0.ImageID) AS Pri
    FROM            Items AS Items_1 INNER JOIN
                             Attribs AS ra0 ON Items_1.ImageID = ra0.ImageID LEFT OUTER JOIN
                             v_DisplayStockPrice AS v_DisplayStockPrice_1 ON Items_1.ImageID = v_DisplayStockPrice_1.ImageID INNER JOIN
                             Attribs AS ra1 ON ra0.ImageID = ra1.ImageID
    WHERE        (Items_1.deleted NOT IN (1, 2)) AND (Items_1.SubcategoryID2 = 'ORD')
    ORDER BY Pri, Items_1.AddDate DESC

So I came up with this syntax.

SELECT DISTINCT Items_1.ImageID, Items_1.SubcategoryID2, Items_1.AddDate, MAX(ra0.DescPriority) AS Pri
FROM            Items AS Items_1 INNER JOIN
                         Attribs AS ra0 ON Items_1.ImageID = ra0.ImageID LEFT OUTER JOIN
                         v_DisplayStockPrice AS v_DisplayStockPrice_1 ON Items_1.ImageID = v_DisplayStockPrice_1.ImageID INNER JOIN
                         Attribs AS ra1 ON ra0.ImageID = ra1.ImageID
WHERE        (Items_1.deleted NOT IN (1, 2)) AND (Items_1.SubcategoryID2 = 'ORD')
GROUP BY Items_1.ImageID, Items_1.SubcategoryID2, Items_1.AddDate
ORDER BY Pri, Items_1.AddDate DESC

Which SQL syntax is better? Or is there better way to write this Query?

Answer 1

The second one looks better and probably performs better, but really you should use Query Analyzer. It will tell you exactly which one is better:
http://msdn.microsoft.com/en-us/library/aa216945(v=sql.80).aspx

Debug query performance problems. (Show Execution Plan, Show Server Trace, Show Client Statistics, Index Tuning Wizard)

Here’s a description of how to use the query execution plan:
http://www.sql-server-performance.com/2006/query-execution-plan-analysis/