Re: 7.0.3 and 7.1.3 different results?
От | Josh Berkus |
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Тема | Re: 7.0.3 and 7.1.3 different results? |
Дата | |
Msg-id | web-140986@davinci.ethosmedia.com обсуждение исходный текст |
Ответ на | Re: 7.0.3 and 7.1.3 different results? (Stephan Szabo <sszabo@megazone23.bigpanda.com>) |
Список | pgsql-sql |
Stephan, > Actually it seems to me that one NULL row is correct... > > 7.9 <query specification> > 1) Case: > a) If T is not a grouped table, then You are correct according to the SQL spec. However, depending on what interface I use for the database, I can get an empty recordset rather than a single NULL row. This has more to do with the interface translation (such as ODBC) than it does with what PostgreSQL is returning. Partly I think this is DB vendors and interpreters getting confused over a consistency issue between SELECT SUM() and SELECT SUM() ... GROUP BY. SELECT sum(totalamount) FROM invoices WHERE invoice_no > invoice_no; ----------- NULL SELECT invoice_no, sum(totalamount) FROM invoices WHERE invoice_no > invoice_no GROUP BY invoice_no; invoice_no|sum -------------- (empty recordset) Obviously not particularly troublesome behavior, as these results seem to be more or less consistent across most vendor implementations. Plus in many languages the tests for NULL and empty recordset overlap or are easily combined. And this is pretty clearly defined in SQL 92, as you point out. -Josh P.S. Can you answer my question about indexing, please please? ______AGLIO DATABASE SOLUTIONS___________________________ Josh Berkus Complete informationtechnology josh@agliodbs.com and data management solutions (415) 565-7293 for law firms, small businesses fax 621-2533 and non-profit organizations. San Francisco
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