On Mon, 26 Aug 2013 19:03:39 +0000 Roman Fleysher <roman.fleys...@einstein.yu.edu> wrote:
> However, sometimes, in comparison we want to ignore some of the > attributes, or compare derived ones. Many busses can carry 25 people, > and may be considered equal if we simply need to transport people. > Busses certainly differ by other attributes. Busses might indeed differ in many ways, but if you make NAME the primary key for BUSSES, the rule is not "compare BUSSES, ignoring columns other than NAME". The rule is "compare BUSSES.NAME". > it is the comparison ( "=", BETWEEN, IN , etc) statements that must > be modified This not a syntax issue. Equality is deeply embedded in the system, in many places where there's no SQL in play (e.g. keys). It's a system of types and operators. We can already convert between types and compare them. If you can show some kind of comparison that *cannot* be done via type conversion using the operators exactly as they are, you might have a point. --jkl _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
