I was checking for Update only if condition will match. In fact it can be any operation like SELECT,INSERT,UPDATE or DELETE
I think hint given by you using count() function will do the required. So here If condition matches then count will return nonzero value & based on that I can continue further. Thanks On Fri, Aug 2, 2013 at 4:15 PM, Hick Gunter <h...@scigames.at> wrote: > Please describe in simple words what you are trying to do. > > UPDATE <table> SET <field>=<value> WHERE <condition> > > Will change the value of <field> in all records of the <table> that > satisfy the <condition>. > > You seem to be expecting that the field is changed also in records that do > not satisfy the condition. > > Or perhaps you really want something like: > > BEGIN; > SELECT COUNT() FROM <table> WHERE <condition>; > if count == 0 > raise exception > else > UPDATE ... > COMMIT > > -----Ursprüngliche Nachricht----- > Von: techi eth [mailto:techi...@gmail.com] > Gesendet: Freitag, 02. August 2013 12:36 > An: General Discussion of SQLite Database > Betreff: Re: [sqlite] Where Clause > > Is their any Query format which can change the value based on conditional > expression is TRUE!!! > > Thanks.. > > Techi - > > > On Fri, Aug 2, 2013 at 2:11 PM, Hick Gunter <h...@scigames.at> wrote: > > > The SQL you gave translates to > > > > "Change the 'Name' field to have the value 'test' in all records where > > the 'ID' field has the value 2". > > > > If there is no such record, then SQL has nothing to do and very > > successfully does exactly nothing. > > > > SQL is "set oriented" and update operations on empty sets always succeed. > > > > I guess you are thinking along procedural/file oriented lines as in > > pseudocode > > > > record.id = 2; > > error = readwithlock( file, byID, &record ); > > if (error) raise exception; > > record.name = 'test'; > > error = updatewithunlock ( file, &record ); > > if (error) raise exception; > > > > SQLite implements UPDATE as a SELECT followed by REPLACE statemenst as > > if written like > > > > (INSERT OR) REPLACE INTO table SELECT id,'test' FROM table WHERE > > id = 2; > > > > Which is equivalent to (naïve, not using index) pseudocode like > > > > open( file ); > > while (! eof( file ) ) > > { > > error = readseqwithlock( file, &record ); > > if (error) raise exception; > > if (record.id == 2) > > { > > record.name = 'test'; > > error = updatewithunlock( file, &record ); > > if (error) raise exception; > > } else { > > error = unlock( file ); > > if (error) raise exception; > > } > > } > > > > HTH > > Gunter > > > > -----Ursprüngliche Nachricht----- > > Von: techi eth [mailto:techi...@gmail.com] > > Gesendet: Freitag, 02. August 2013 10:15 > > An: General Discussion of SQLite Database > > Betreff: [sqlite] Where Clause > > > > Come across one issue with conditional query execution. > > > > Query: UPDATE COMPANY SET Name= 'test' WHERE ID = 2; According to my > > understanding if no ID = 2 is present in table then error should > > return but it return with SQLITE_OK however Name value is not changed. > > > > Cheers - > > Techi > > _______________________________________________ > > sqlite-users mailing list > > sqlite-users@sqlite.org > > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > > > > > ---------------------------------------------------------------------- > > ---- > > Gunter Hick > > Software Engineer > > Scientific Games International GmbH > > Klitschgasse 2 - 4, A - 1130 Vienna, Austria FN 157284 a, HG Wien > > Tel: +43 1 80100 0 > > E-Mail: h...@scigames.at > > > > This e-mail is confidential and may well also be legally privileged. > > If you have received it in error, you are on notice as to its status > > and accordingly please notify us immediately by reply e-mail and then > > delete this message from your system. Please do not copy it or use it > > for any purposes, or disclose its contents to any person as to do so > > could be a breach of confidence. Thank you for your cooperation. > > _______________________________________________ > > 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 > > > -------------------------------------------------------------------------- > Gunter Hick > Software Engineer > Scientific Games International GmbH > Klitschgasse 2 – 4, A - 1130 Vienna, Austria > FN 157284 a, HG Wien > Tel: +43 1 80100 0 > E-Mail: h...@scigames.at > > This e-mail is confidential and may well also be legally privileged. 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