Comments on: Access queries http://smurfonspreadsheets.wordpress.com/2008/04/22/access-queries/ Simon Murphy on professional spreadsheet development stuff Fri, 08 Aug 2008 19:53:59 +0000 http://wordpress.org/?v=MU By: Doug Glancy http://smurfonspreadsheets.wordpress.com/2008/04/22/access-queries/#comment-11379 Doug Glancy Tue, 13 May 2008 00:39:34 +0000 http://smurfonspreadsheets.wordpress.com/?p=570#comment-11379 Great conversation. I'm just starting to program Access and this post gave me the inspiration to write a class to handle Select Querydefs to feed into reports. Great conversation. I’m just starting to program Access and this post gave me the inspiration to write a class to handle Select Querydefs to feed into reports.

]]> By: JP http://smurfonspreadsheets.wordpress.com/2008/04/22/access-queries/#comment-11288 JP Tue, 29 Apr 2008 03:43:12 +0000 http://smurfonspreadsheets.wordpress.com/?p=570#comment-11288 I use MS Query to build a SQL connection string, save the query file, then just open it from Excel 2003 VBA using the OpenDatabase Method. That executes the query without any need to touch Access (which personally I detest). Just assign the macro to a toolbar button and POOF! anyone with Excel can query the db. If you have a copy of the book 'Managing Data with Microsoft Excel', there's an excellent section about querying an Access database from Excel. --JP I use MS Query to build a SQL connection string, save the query file, then just open it from Excel 2003 VBA using the OpenDatabase Method. That executes the query without any need to touch Access (which personally I detest). Just assign the macro to a toolbar button and POOF! anyone with Excel can query the db. If you have a copy of the book ‘Managing Data with Microsoft Excel’, there’s an excellent section about querying an Access database from Excel.

–JP

]]> By: Simon http://smurfonspreadsheets.wordpress.com/2008/04/22/access-queries/#comment-11225 Simon Thu, 24 Apr 2008 09:48:36 +0000 http://smurfonspreadsheets.wordpress.com/?p=570#comment-11225 Rob Don't you base views on views or queries on queries? I may do a base groupby, and then have various views of that, perhaps further summarised, or filtered or joined. Not stuff like dates, they would probably go in as parameters, but I would join to a product type table, of a geo one. I guess stability is the key, unstable - param, stable - view of view? I'll dig out an example for a future post, as I suspect we are thinking of different scenarios. Rob
Don’t you base views on views or queries on queries?

I may do a base groupby, and then have various views of that, perhaps further summarised, or filtered or joined. Not stuff like dates, they would probably go in as parameters, but I would join to a product type table, of a geo one. I guess stability is the key, unstable - param, stable - view of view?

I’ll dig out an example for a future post, as I suspect we are thinking of different scenarios.

]]> By: Rob Bruce http://smurfonspreadsheets.wordpress.com/2008/04/22/access-queries/#comment-11223 Rob Bruce Thu, 24 Apr 2008 06:27:32 +0000 http://smurfonspreadsheets.wordpress.com/?p=570#comment-11223 Maintenance. With an 'a'. I blame the teachers. Maintenance. With an ‘a’. I blame the teachers.

]]> By: Rob Bruce http://smurfonspreadsheets.wordpress.com/2008/04/22/access-queries/#comment-11222 Rob Bruce Thu, 24 Apr 2008 06:23:23 +0000 http://smurfonspreadsheets.wordpress.com/?p=570#comment-11222 Simon, "I assumed Dick meant ’select * from qryXXX…’ where … means WHERE or HAVING or whatever. I build queries up just the same based on others, does anyone else?" Wouldn't this be a textbook example of distributing logic across different layers of your application? This looks like a maintenence nightmare. Wouldn't it be better to make qryXXX as param query so that the WHERE logic happens with the rest of your app's data access logic? Rob Simon,

“I assumed Dick meant ’select * from qryXXX…’ where … means WHERE or HAVING or whatever. I build queries up just the same based on others, does anyone else?”

Wouldn’t this be a textbook example of distributing logic across different layers of your application? This looks like a maintenence nightmare. Wouldn’t it be better to make qryXXX as param query so that the WHERE logic happens with the rest of your app’s data access logic?

Rob

]]> By: alastair http://smurfonspreadsheets.wordpress.com/2008/04/22/access-queries/#comment-11215 alastair Wed, 23 Apr 2008 08:30:19 +0000 http://smurfonspreadsheets.wordpress.com/?p=570#comment-11215 I have always used DAO - don't know why. Access and performance is something of an art rather than a science!!! I have always used DAO - don’t know why. Access and performance is something of an art rather than a science!!!

]]> By: Dick Kusleika http://smurfonspreadsheets.wordpress.com/2008/04/22/access-queries/#comment-11207 Dick Kusleika Tue, 22 Apr 2008 20:56:26 +0000 http://smurfonspreadsheets.wordpress.com/?p=570#comment-11207 Yeah, I was going to sign my name Littlus Dickus, but that's the kind of thing that follows a guy around. I like the pre-compiled argument. And I never thought of the SQL statement being saved as a property of the QD, but that makes sense. I should admit that I use ADO even when connecting to Jet (because I'm lazy), so I'm a bit of hypocrite for bringing up performance issues in the first place. Yeah, I was going to sign my name Littlus Dickus, but that’s the kind of thing that follows a guy around.

I like the pre-compiled argument. And I never thought of the SQL statement being saved as a property of the QD, but that makes sense. I should admit that I use ADO even when connecting to Jet (because I’m lazy), so I’m a bit of hypocrite for bringing up performance issues in the first place.

]]> By: Simon http://smurfonspreadsheets.wordpress.com/2008/04/22/access-queries/#comment-11206 Simon Tue, 22 Apr 2008 20:27:12 +0000 http://smurfonspreadsheets.wordpress.com/?p=570#comment-11206 Rob I assumed Dick meant 'select * from qryXXX...' where ... means WHERE or HAVING or whatever. I build queries up just the same based on others, does anyone else? Marcus yes I do that, I have SQL (and MDX) generator library code. Performance wise I'd expect querydefs to have the edge, but I don't know, havent tested it, and no idea whether it would be material. It would depend on how you access the db though, I imagine DAO is faster than ADO is faster than ADO.net? Anyone got any decent performance links? cheers Simon Rob
I assumed Dick meant ’select * from qryXXX…’ where … means WHERE or HAVING or whatever. I build queries up just the same based on others, does anyone else?

Marcus yes I do that, I have SQL (and MDX) generator library code.

Performance wise I’d expect querydefs to have the edge, but I don’t know, havent tested it, and no idea whether it would be material. It would depend on how you access the db though, I imagine DAO is faster than ADO is faster than ADO.net?
Anyone got any decent performance links?
cheers
Simon

]]> By: Rob Bruce http://smurfonspreadsheets.wordpress.com/2008/04/22/access-queries/#comment-11205 Rob Bruce Tue, 22 Apr 2008 19:29:32 +0000 http://smurfonspreadsheets.wordpress.com/?p=570#comment-11205 "This gain used to be easily seen in earlier versions of Access and on earlier slow machines and networks." I was going to comment that "Select * from qryXXXX" is probably doing the query twice (well, doing the query and then querying the result of the query) and that the use of the '*' also makes Jet do more work in finding out what fields it should be dealing with, but I think that, generally at least, such micro optimisation is becoming less relevant as hardware becomes faster and cheaper. “This gain used to be easily seen in earlier versions of Access and on earlier slow machines and networks.”

I was going to comment that “Select * from qryXXXX” is probably doing the query twice (well, doing the query and then querying the result of the query) and that the use of the ‘*’ also makes Jet do more work in finding out what fields it should be dealing with, but I think that, generally at least, such micro optimisation is becoming less relevant as hardware becomes faster and cheaper.

]]> By: Biggus Dickus http://smurfonspreadsheets.wordpress.com/2008/04/22/access-queries/#comment-11202 Biggus Dickus Tue, 22 Apr 2008 17:32:12 +0000 http://smurfonspreadsheets.wordpress.com/?p=570#comment-11202 Dick (what a great name eh?): "There has to be some kind of performance hit using qeurydefs, doesn’t there?" Actually I have always thought the opposite is the case because a saved query is pre-compiled and Jet likes that. This gain used to be easily seen in earlier versions of Access and on earlier slow machines and networks. Even though I haven't tested it in recent versions (where's Ken Getz when we need him ??), I have always thought it still had some value. If anything it's neutral not a negative. Biggus Dickus Dick (what a great name eh?):

“There has to be some kind of performance hit using qeurydefs, doesn’t there?”

Actually I have always thought the opposite is the case because a saved query is pre-compiled and Jet likes that.
This gain used to be easily seen in earlier versions of Access and on earlier slow machines and networks. Even though I haven’t tested it in recent versions (where’s Ken Getz when we need him ??), I have always thought it still had some value. If anything it’s neutral not a negative.

Biggus Dickus

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