Hello! On Monday 01 March 2010 08:05:06 Darren Duncan wrote: > Alexey Pechnikov wrote: > > Hello! > > > > On Thursday 25 February 2010 02:53:32 Igor Tandetnik wrote: > >> http://www.sqlite.org/datatype3.html > >> For conversions between TEXT and REAL storage classes, SQLite considers > >> the conversion to be lossless and reversible if the first 15 significant > >> decimal digits of the number are preserved. > > > > The SQLite datatyping is very different from other RDBMS: > > > > sqlite> select 1='1'; > > 0 > > > > Postgres: > > template1=# select 1='1'; > > ?column? > > ---------- > > t > > > > And there are a lot of problem as result, see some tests here: > > http://sqlite.mobigroup.ru/src/wiki?name=tclsqlite > > > > I don't know how to fix it in the SQLite core. My patch for > > the tclslite interface can't resolve the internal problem... > > It would seem to me that asking [1='1'] *should* return false because the > numeric and character string value domains are logically disjoint, so no > value > from one could ever equal a value from another, and so SQLite's answer is > correct.
See http://sqlite.org/datatypes.html: "If both inputs look like well-formed numbers, then they are converted into floating point values using atof() and compared numerically." And so 1 may be equal to 1. > As for your Postgres, what version of Postgres are you using? template1=# select version(); version ---------------------------------------------------------------------------------------------------------------- PostgreSQL 8.1.15 on i486-pc-linux-gnu, compiled by GCC cc (GCC) 4.1.2 20061115 (prerelease) (Debian 4.1.1-21) > AFAIK, since at > least Postgres 8.3, Postgres became stricter and stopped doing implicit > casting > between disjoint data types, which would be required for [1='1'] to be true. It's a registered bug in 8.3.0 release. 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
