> As you can see above 1 is always equal to '1'. You're wrong. As you can see from your own examples when you store 1 or '1' in the field a of type "text" then comparison of field a to either 1 or '1' is always true. And at the same time comparison of constant 1 to constant '1' is always false. Do you feel the difference in these test cases? Try to change something in your test case. E.g. declare your field a as type "blob" or as type "any dummy type you like" and you'll suddenly see that 1 is not always equal to '1'.
> Do you know some language where 1='1' or 1!='1' randomly? I don't know of any language that does anything randomly and I know that SQLite doesn't do these comparisons "randomly" either. Have you ever read the document I pointed you to? You better do because it explains all subtle differences in your test cases that you do not happen to see now. > The internal representation of the integer and of the double is different > and internal conversation is needed. Most modern languages make this > for string values too. Wow, I have never seen so far anybody calling C and C++ "not a modern language". Or you have already proposed this feature to C++0x standard? Pavel P.S. Do you realize that as long as you make some accusations of type "SQLite doesn't work like I want it to" without ever trying to understand why SQLite works that way nobody will treat you seriously? On Sat, Oct 31, 2009 at 5:29 AM, Alexey Pechnikov <pechni...@mobigroup.ru> wrote: > Hello! > > On Saturday 31 October 2009 02:31:44 Simon Slavin wrote: >> >> On 30 Oct 2009, at 9:47pm, Alexey Pechnikov wrote: >> >> > Now SQLite think that 1 is equal to '1' in some causes and think >> > different in other. >> >> Just like every other language, once you get into it you have to learn >> how the language works to understand what's going on. Your problem is >> not really with the comparison, it's with what happens to a value when >> it is stored in a table. Strongly typed languages usually do one of >> two things: >> >> A) not allow the comparison at all (you get a syntax error from the >> compiler) >> >> B) say that two values of different types never equal one-another > > You did forget the third way: > > C) convert values to same type before comparision > > In C the comparision some of different types is valid: > int x =1; > double y=2; > if (y>x) ... > The internal representation of the integer and of the double is different > and internal conversation is needed. Most modern languages make this > for string values too. > > In Tcl value can has string or numeric internal representation and is > converted > before comparison. When values can have the same type and is equal than the > result of equality check is positive. When values doesn't have the same type > or have the same type but isn't equal than equality check is negative. > > 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 > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
