Thanks all for the pointer to go with the relational algebra approach. I
will work with that route, I did have a follow up question on that path. Is
there support in the RelBuilder to apply predicates on JSON data stored in
a single column in a table?
I noted tests in RelToSqlConverterTest for queries on json but did not see
one which used the RelBuilder to apply predicates on a field which carries
JSON data. Is there a convention to represent a field inside a json?
Example: table t has column a which has a json inside say { "x" :
"some-string-value", "y": some-integer-value } and say I want to express a
predicate like y > some-ceiling-value.
-Sandeep
On Wed, Nov 24, 2021 at 3:00 AM Florent Martineau <[email protected]>
wrote:
> Hi Sandeep,
>
> I'm no expert so take what I'm saying with a grain of salt.
>
> I use Calcite to generate queries by using the RelBuilder, which will
> create RelNodes that I can then convert to SQL when I need to execute the
> query.
>
> From my understanding, if we use Relational Algebra it's because it's much
> easier to manipulate and reason with, than SQL. Therefore it makes more
> sense for me to build the query using relational algebra and then convert
> it back to SQL.
>
> TL;DR: I don't use SQL Nodes to build queries, but RelBuilder then
> RelToSQLConverter.
>
> Hope this helps,
>
> Florent
>
> On Wed, Nov 24, 2021, 11:38 AM Sandeep Nayak <[email protected]>
> wrote:
>
> > Hello,
> >
> > I have been looking for a library which will allow me to use an object
> tree
> > to generate a SQL. Calcite came up in my search but after taking a look
> at
> > the codebase my conclusion is that Calcite provides the ability to parse
> > SQL statements into an object tree represented as SQLNode (and derived
> > classes) instances which subsequently can be used to perform
> optimizations
> > by generating relational algebra for the logical query.
> >
> > Calcite however does not provide classes which can be used to assemble a
> > tree and generate SQL statements. From the contracts at least SQLNode
> takes
> > in a Parser position and there are no other contracts which indicate such
> > an option. Can someone confirm if this is inaccurate?
> >
> > If not Calcite, are there other open source libraries out there which
> allow
> > this?
> >
> > Thanks in advance.
> >
> > -Sandeep
> >
>
