Hi Nick, On Nov 25, 2010, at 2:09 PM, Nick Shaw wrote:
> As Igor points out, that may not fail if the corruption is in a table > you don't query. > > In this case, the databases I'm working with are either small enough for > the speed of an integrity check not to be an issue, or the integrity of > the database is more important than a delayed DB open (which happens in > a seprate thread to my apps' main GUI, so the user won't notice an issue > anyway). > > Thanks for all the help peeps, > Nick. Agreed. However, the original email looks like it's a two-part question: opening non-SQLite files and detecting corrupted databases. Looks like the solution would be to integrate a method combining both Igor and Simon's solution: 1) SELECT on sqlite_master. All SQLite3 databases contain it, so it would fail right away is it wasn't a valid database. 2) Issue a "PRAGMA integrity_check" statement, if (1) succeeds. However, I'm wondering whether (1) is redundant. If the integrity check detects right away that the file is not a SQLite3 database, then we're good. But if the integrity check reads the whole file before failing, perhaps running (1) would not be such a bad after all. Also, if there is a need to know whether a database is corrupted, an optimization seems to be to issue "PRAGMA integrity_check (1)" statement, which would bail out at the first sign of trouble. As stated in the docs: http://www.sqlite.org/pragma.html > PRAGMA integrity_check; > PRAGMA integrity_check(integer) > > This pragma does an integrity check of the entire database. It looks for > out-of-order records, missing pages, malformed records, and corrupt indices. > If any problems are found, then strings are returned (as multiple rows with a > single column per row) which describe the problems. At most integer errors > will be reported before the analysis quits. The default value for integer is > 100. If no errors are found, a single row with the value "ok" is returned. Cheers, -- Tito _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
