Kevin Grittner <kgri...@ymail.com> writes: > = equals (but doesn't necessarily look the same as) > === IS NOT DISTINCT FROM as an operator > ==== reserved for "has no user-visible differences from" > ===== stored image is the same
I understand the need for more than one equality operator and my programming language of choice exposes eq, eql, equal and equalp for solving a very similar situation. Oh, and also offers = and string= and string-equal, among others. My vote goes against using a different number of the same character to name the operators though, as that's not visually helpful enough IMO. In yet another language whose grammar took inspiration with Prolog, dealing with binary is made with explicitely using the bit syntax expression where any datum is boxed into << and >>. http://erlang.org/doc/reference_manual/expressions.html#id78513 It might not be practical to do the same in SQL and have either the following syntax example or even a unary "bit representation" operator to do the same: SELECT <<row(expression, here)>> = <<column_name>> … That would probably prevent using indexes? It might be inspiration to name the bit-comparison operator something like <<=>> though, or =><= or something else. If only we could force the usage of unicode for the SQL input itself… I'm sure there's a unicode glyph perfect for what we want here… About IS NOT DISTINCT FROM, I would propose something where NOT and DISTINCT are kept as concepts. Not usually is expressed with ! and we already have a bunch of "same as" or "matches" operators with ~, so: <~> IS DISTINCT FROM !<~> IS NOT DISTINCT FROM Regards, -- Dimitri Fontaine http://2ndQuadrant.fr PostgreSQL : Expertise, Formation et Support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
