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From Andrew O <ao2596...@gmail.com>
Subject Re: Parsing DB2 sql statements
Date Thu, 06 Jun 2019 12:42:28 GMT
Thanks for the replies.

@Yuzhao unfortunately I won't be able to change the input sql to add the
quotes,  so as you point out the UDF may have issues with the reserved
word.

@Hongze, Yes, I'm only interested in parsing.  I had tried the Babel parser
without success (on v1.19.0).   However that's great / fortunate that there
have been recent changes to support additional syntax.   Thanks for the
JIRA ticket reference.   The new test cases seem to show similar sql now
being supported.   So I will give that a try.

Andrew

On Thu, 6 Jun 2019, 13:19 Hongze Zhang, <notifyzhz@126.com> wrote:

> Hi Andrew,
>
> If you are focusing parsing only, I believe you can just use the babel
> parser - in babel we have added support for DATE function via CALCITE-3022.
> The thing is you need to compile Calcite's code by yourself - 1.20.0 hasn't
> been released yet.
>
> Hongze
>
> > On Jun 6, 2019, at 19:06, Andrew O <ao2596599@gmail.com> wrote:
> >
> > I'm doing a project trying to parse some IBM DB2 sql expressions (to
> > analyze table / column usages).
> >
> > To note,
> > 1) these are existing ad-hoc user queries so I can't change their syntax
> > 2)  I don't have a connection / schema for the database,  but my
> > understanding is that this shouldn't be required by Calcite for this
> > kind of work.
> >
> > Currently I'm hitting some parsing issues with queries like
> >
> >    select Date(x.col1), x.col2 from myTable x
> >
> > It fails parse at the point of the Date function call. This is trying to
> > use the function to convert the value of col1 to a date (almost similar
> to
> > a cast/convert).
> >
> >
> https://www.ibm.com/support/knowledgecenter/en/SSEPEK_11.0.0/sqlref/src/tpc/db2z_bif_date.html
> >
> >
> > My current thinking would be that this  may need changes to the parser
> > grammar (through an extension?). Or perhaps this could be registered as a
> > custom User Defined Function of some kind (although Date seems like a
> > reserved word)?
> >
> > Is this the right thinking,  or is there another approach I could look
> at?
> >
> > Thanks in advance
> >
> > Andrew
>
>

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