That was my first attempt and it worked, but Julian pointed out that I can support a type without modifying the parser (which I prefer) but I couldn't get it to return the column type name as I wish.
Thanks, Gelbana On Mon, Jun 3, 2019 at 3:13 AM Yuzhao Chen <[email protected]> wrote: > You don’t need to, just define a new type name in parser[1] and translate > it to VARCHAR is okey. > > [1] > https://github.com/apache/calcite/blob/b0e83c469ff57257c1ea621ff943ca76f626a9b7/server/src/main/codegen/config.fmpp#L375 > > Best, > Danny Chan > 在 2019年6月3日 +0800 AM6:09，Muhammad Gelbana <[email protected]>，写道： > > That I understand now. But how can I support casting to TEXT and having > the > > returned column type name as TEXT (ie. Not VARCHAR) ? > > > > Thanks, > > Gelbana > > > > > > On Sun, Jun 2, 2019 at 7:41 PM Julian Hyde <[email protected]> wrote: > > > > > The parser should only parse, not validate. This is a very important > > > organizing principle for the parser. > > > > > > If I write “x :: text” or “x :: foo” it is up to the type system > > > (implemented in the validator and elsewhere) to figure out whether > “text” > > > or “foo” are valid types. > > > > > > Logically, “x :: foo” is the same as “CAST(x AS foo)”. The parser > should > > > produce the same SqlCall in both cases. Then the parser’s job is done. > > > > > > Julian > > > > > > > > > > On Jun 2, 2019, at 6:42 AM, Muhammad Gelbana <[email protected]> > > > wrote: > > > > > > > > I'm trying to support the PostgreSQL TEXT type[1]. It's basically a > > > VARCHAR. > > > > > > > > As Julian mentioned in his comment on Jira, I don't need to define a > > > > keyword to achieve what I need so I tried exploring that and here is > > > what I > > > > observed so far: > > > > > > > > 1. If I define a new keyword in the parser, I face no trouble > whatsoever > > > > except for the numerous wiring I need to do for RexToLixTranslator, > > > > JavaTypeFactoryImpl, SqlTypeAssignmentRules and SqlTypeName. I won't > be > > > > suprised if I'm missing anything but doing what I did at first > managed to > > > > get my queries through. > > > > > > > > 2. If I define the type by plugging it in through the root schema, I > face > > > > two problems: a) The field cannot be declared as nullable because the > > > query > > > > I'm using for testing gets data from (VALUES()) which doesn't produce > > > null > > > > values, so an exception is thrown. b) The returned column type name > is > > > > VARCHAR (although I delcared the new plugged type name to be TEXT), > the > > > > returned type number is valid though (Types.VARCHAR = 12) > > > > > > > > I think I'm doing something wrong that causes (2.a) but (2.b) seems a > > > like > > > > a bug to me. What do you think ? > > > > > > > > [1] https://issues.apache.org/jira/browse/CALCITE-3108 > > > > > > > > Thanks, > > > > Gelbana > > > > > > >
