On Thu, Jul 3, 2014 at 7:19 AM, Hick Gunter <[email protected]> wrote:
> Not possible in SQL. "b.answer || a.epxr" is a string. It does not get > evaluated. Unless you write your own eval() function that executes its > parameter as an SQL statement, which is going to be very slow as each > result row needs to prepare, step and finalize its very own statement. > All correct. Note, though, that SQLite is reentrant so you can write such an eval() function. And our test harnesses for SQLite do so and use that function as part of testing. And eval() is faster than you might expect :-) > > -----Ursprüngliche Nachricht----- > Von: Keshav Tadimeti [mailto:[email protected]] > Gesendet: Mittwoch, 02. Juli 2014 20:18 > An: [email protected] > Betreff: [sqlite] evaluate expression stored in a column > > Hello all > > I have the following requirement: > > Table a > -------- > id int > expr text > result integer > > Insert into a values (10,' > 2'); > > Table b > ------- > id int > answer text > > Insert into b values (10,'10'); > > I need to evaluate the condition that 10 > 2 and store the result of that > expression in a.result. > > I am failing to have the expression evaluated. > > select b.answer || a.expr from a inner join b on a.id = b.id; -- gives 10 > > 2 > I need to see 1 (since 10 > 2). > > Kindly help!! > > Best > -- > Using Opera's mail client: http://www.opera.com/mail/ > _______________________________________________ > sqlite-users mailing list > [email protected] > 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: [email protected] > > 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 > [email protected] > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > -- D. Richard Hipp [email protected] _______________________________________________ sqlite-users mailing list [email protected] http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
