Posted by Erland Sommarskog on 06/07/06 21:45

octangle (idea.vortex@gmail.com) writes:
> /* Query attempt #4 (Hugo) */
>
> SELECT RegJrnID, MAX(InvoiceDate) as "InvoiceDate", MAX(InvoiceNumber)
> as "InvoiceNumber", MAX(TaxableAmount) as "TaxableAmount"
> FROM t1
> GROUP BY RegJrnID
> HAVING COUNT(*) = 1
>
> I talked to a few folks around the office and none of us had ever
> though to use MAX() to force values out of a query using a GROUP BY
> clause...
>...
> My question with this is, "Is this technique safe for all major DBs
> (Oracle, SQL Server, DB2 and MySQL) and will it work with all column
> types?"

Yes, it should on any RDBMS worth the name, as it is very plain standard
SQL.

Then again, MySQL has so many funny quirks, I suspect that one should
never take anything for granted with that engine.


--
Erland Sommarskog, SQL Server MVP, esquel@sommarskog.se

Books Online for SQL Server 2005 at
http://www.microsoft.com/technet/prodtechnol/sql/2005/downloads/books.mspx
Books Online for SQL Server 2000 at
http://www.microsoft.com/sql/prodinfo/previousversions/books.mspx

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