Good day all, Thank you for your replies.
Yes, I can provide the data if required, although I don't think it is needed, as the bug is in the user's code. The point about what happens if several timestamps have the same value is valid, and in this case, I think is the explanation. sqlite> SELECT id, timestamp, data_blob FROM data WHERE timestamp = (SELECT MIN(timestamp) FROM data WHERE stream_num = 2) ; 3|12946000654830|☻ 4|12946000654830|☺ 5|12946000654830|☺ sqlite> SELECT id, timestamp, data_blob FROM data WHERE timestamp = (SELECT MIN(timestamp) FROM data WHERE stream_num = 2) and stream_num = 2; 4|12946000654830|☺ sqlite> SELECT id, timestamp, data_blob FROM data WHERE stream_num = 2 order by timestamp asc; 4|12946000654830|☺ Obviously, there are several records with the same timetamp, and putting the restriction on the stream num ensures that the right one is picked. regards, Adam On Mon, Feb 3, 2014 at 12:47 PM, Richard Hipp <d...@sqlite.org> wrote: > Can you provide data? Without some sample data, we cannot tell if the > answer SQLite is providing is right or wrong. > > > On Mon, Feb 3, 2014 at 12:25 PM, Adam Devita <adev...@verifeye.com> wrote: > > > Good day, > > > > I'm debugging some code that uses 3.8.1, and I've tried just upgrading to > > 3.8.3, which didn't work. The observation is that > > > > This query: > > SELECT id, data_blob FROM data WHERE timestamp = (SELECT MIN(timestamp) > > FROM data WHERE stream_num = ?) LIMIT 1 > > > > seems to occasionally produce a wrong result (the content of data_blob is > > incorrect given the values of stream_num) > > > > yet this query > > SELECT id, data_blob FROM data WHERE stream_num = ? order by timestamp > asc > > LIMIT 1 > > > > seems just fine, insofar as the same tests on the same data have not hit > > any of the error condition / contradiction. > > > > in both cases sqlite3_bind_int(pStmt, 1, (int)nStream); is used for > > parameter ? > > > > > > We are using an in memory database as a smarter queue where timestamp > data > > gets inserted, and if the db size is sufficient (30 to 40 records) the > > above query lets us pop the earliest timestamp (which is stored as int64 > > via sqlite3_bind_int64). > > > > Is this a possible bug or am I missing something? Using the backup api > to > > look at it from a file > > sqlite>.schema > > CREATE TABLE data ( id INTEGER PRIMARY KEY, timestamp BIGINT NOT NULL, > > stream_num TINYINT, source_seq_num TINYINT, > > event_seq_num INT, data_address BIGINT NOT NULL, data_blob BLOB NOT > NULL); > > > > sqlite> SELECT id, data_blob FROM data WHERE stream_num = 2 order by > > timestamp asc LIMIT 1; > > 4|☺ > > sqlite> SELECT id, data_blob FROM data WHERE timestamp = (SELECT > > MIN(timestamp) FROM data WHERE stream_num = 2) LIMIT 1; > > 3|☻ > > sqlite> > > > > regards, > > Adam DeVita > > _______________________________________________ > > sqlite-users mailing list > > sqlite-users@sqlite.org > > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > > > > > -- > D. Richard Hipp > d...@sqlite.org > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
