Alexey, I can certainly tell you what is causing this behaviour:
When sqlite does a comparison, it checks the *column* affinity from both sides. In your example, neither sides come from a column, but are constants. Therefore, sqlite uses the NONE affinity on comparison (I think, but I haven't checked, therefore doing a binary comparison). If both sides of the comparison are columns, then it will choose a "best-match" affinity; if only one side is from a column it will use the affinity from that column. For reference, have a look at the function 'sqlite3CompareAffinity' in expr.c. However, you can fool it using... select cast(1 as integer)='1' This works because the cast operator assigns an affinity and therefore, since one side has an assigned affinity, the comparison does the conversion of the second side. Plus it adds only a single op to the vdbe code, which turns out as an almost no-op since it is integer already. Now, it is probable that the core can be patched as you request by assigning affinity to constants during parsing, but I haven't had an opportunity to look into it and I would have to check very thoroughly that it will not brake something else if I do patch it for you. At this precise moment, I cannot look into it for you, but maybe later in the week I will have time. Kind regards Will Alexey Pechnikov <pechni...@mobigroup.ru> wrote on 28/02/2010 19:41:31: > Alexey Pechnikov <pechni...@mobigroup.ru> > 28/02/2010 19:42 > > Bitte antworten an > pechni...@sandy.ru > > An > > wcl...@gfs-hofheim.de > > Kopie > > Thema > > The SQLite datatyping problem > > Hello! > > I did fix the tclsqlite typing as decribed here: http:// > sqlite.mobigroup.ru/src/wiki?name=tclsqlite > But there is the core SQLite problem: > > In PostgreSQL we get > offline1=# select 1='1'; > ?column? > ---------- > t > > And in SQLite it's wrong > sqlite> select 1='1'; > 0 > > May be you know how to fix SQLite core for providing the correct behaviour? > > Best regards, Alexey Pechnikov. > http://pechnikov.tel/ _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
