El dg 26 de 11 del 2006 a les 03:21 +0100, en/na Pawel Lewicki va escriure: > Hi, > I'm trying pyTables as a tool to support RDBMS. > What would be the most efficient way of equivalent of > SELECT f1,f1 sum f3 GROUP BY f1,f2 > Is it supported anyhow? Maybe there is a tutorial explaining different > use-cases from SQL perspective?
Well, as it is said in the FAQ (see [1]), PyTables is, by no means, not designed to work as a replacement of a RDBMS. In particular, it has not integrated support for "GROUP BY" clause. If you want something like this, you will have to do that on your own by using a combination of iterators (see iterrows() and itersquence() methods in [2]) and Python statements. [1]<http://www.pytables.org/moin/FAQ#head-c4ee3c6897ead4d9710afe2a702da239a8405d92> [2] http://www.pytables.org/docs/manual/x2981.html > Great tool, btw. Glad that you like it. -- Francesc Altet | Be careful about using the following code -- Carabos Coop. V. | I've only proven that it works, www.carabos.com | I haven't tested it. -- Donald Knuth ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Pytables-users mailing list Pytables-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/pytables-users
