Re: [Libdbi-drivers-devel] sqlite driver problem?
Balazs Scheidler writes: This sounds doable, however I potentially have hundreds of tables in the database, I'd prefer avoiding having to list all tables when I need to open a new one. This is, admittedly, inconvenient. Hmm, I tried but sqlite reports an error: sqlite create table aaa (a,b,c); sqlite alter table aaa add d; SQL error: duplicate column name: d This looks really screwed. I looked into the SQLite3 interface again to see whether we'd get at more information if we stop using the sqlite3_get_table() function which is just a wrapper around some low-level interface. However, that interface is implemented using callbacks which receive the row data and the row metadata (column names and such). That is, no rows, no metadata. However, there is a PRAGMA table_info(table_name) which may come in handy at this point. We'd have to run a query using this PRAGMA whenever a query returns 0 rows to manually fix the column number in the (empty) libdbi result set. I'll check whether this is doable. regards, Markus -- Markus Hoenicka [EMAIL PROTECTED] (Spam-protected email: replace the quadrupeds with mhoenicka) http://www.mhoenicka.de - This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100url=/ ___ Libdbi-drivers-devel mailing list Libdbi-drivers-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-drivers-devel
[Libdbi-drivers-devel] sqlite driver problem?
Hi, I've been using libdbi in syslog-ng to insert log data into SQL databases. I've an issue with the sqlite driver though: when the result is an empty set, it does not return the column headers - unlike other drivers -, and this causes problems with syslog-ng. To describe the problem I have to give some detail how syslog-ng uses SQL, but please bear with me: syslog-ng creates tables for itself automatically, so if a table does not exist, or does not have the required columns, it creates it or adds the needed columns. For this it needs to detect whether a table exists, using this simple query: SELECT * FROM table WHERE 0=1 MySQL, PgSQL, MSSQL and Oracle returns an empty result set, with the column information in it. SQLite on the other hand returns no rows and no columns either. I don't really know sqlite internals and neither do I know libdbi driver internals, but I was wondering whether this behaviour can be worked around in libdbi, or it is something that I have to live with, and the query above is not a generic, database independent way of finding out table structure? Thanks in advance, -- Bazsi - This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100url=/ ___ Libdbi-drivers-devel mailing list Libdbi-drivers-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-drivers-devel
