Thanks Lai, I beleive your analysis is correct.

Which brings up another question:
Is it ok if we add support for what I'm trying to do here ? I can gladly
work on that but I need to know if it will be accepted.

Thanks,
Gelbana


On Tue, Jun 4, 2019 at 8:38 AM Lai Zhou <[email protected]> wrote:

> @Muhammad Gelbana,I think you just register an alias-name 'TEXT' for the
> SqlType  'VARCHAR'.
> The parser did the right thing here, see
>
> https://github.com/apache/calcite/blob/9721283bd0ce46a337f51a3691585cca8003e399/core/src/main/java/org/apache/calcite/sql/validate/SqlValidatorImpl.java#L1566
> When the parser encountered a 'text' SqlIdentifier, it would get the type
> from the rootSchema, the type was SqlTypeName.VARCHAR here , that you
> registered before.
> If you really need a new sqlType named 'text' rather than an alias-name, I
> guess you need to introduce a new kind of SqlTypeName .
>
>
>
>
> Muhammad Gelbana <[email protected]> 于2019年6月3日周一 下午6:54写道:
>
> > Is that different from what I mentioned in my Jira comment ? Here it is
> > again:
> >
> > Connection connection = DriverManager.getConnection("jdbc:calcite:",
> info);
> >
> >
> connection.unwrap(CalciteConnection.class).getRootSchema().unwrap(CalciteSchema.class).add("
> > *TEXT*", new RelProtoDataType() {
> >
> >             @Override
> >             public RelDataType apply(RelDataTypeFactory factory) {
> >                 return
> > factory.createTypeWithNullability(factory.createJavaType(String.class),
> > false);
> >                 // return
> >
> >
> factory.createTypeWithNullability(factory.createSqlType(SqlTypeName.VARCHAR),
> > false); // Has the same effect
> >             }
> >         });
> >
> > This still returns a column type name of VARCHAR, not *TEXT*.
> >
> > I tried providing the type through the model as the UdtTest does but it's
> > giving me the same output.
> >
> > Thanks,
> > Gelbana
> >
> >
> > On Mon, Jun 3, 2019 at 9:59 AM Julian Hyde <[email protected]> wrote:
> >
> > > User-defined types are probably the way to go.
> > >
> > > > On Jun 2, 2019, at 8:28 PM, Muhammad Gelbana <[email protected]>
> > > wrote:
> > > >
> > > > 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
> > > >>>>
> > > >>>>
> > > >>
> > >
> > >
> >
>

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