Extending Flink's SQL-Parser

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URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/Extending-Flink-s-SQL-Parser-tp30008.html

Hey there,

 

I have to extend Flink's SQL-parser such that it accepts and evaluates select-queries with different syntax.

Furthermore I use Eclipse Oxygen with Maven plugin and Flink Release 1.8.0.

 

What I believe to know:

For parsing SQL-queries Flink-Table uses Apache Calcite's SQL-parser. Flink-Table-Planner is the only module that references the Calcite-Core which contains the parser ("Parser.jj" ?).

Therefore I want to import Flink-Table-Planner and Calcite-Core as local projects in Eclipse and edit the files "config.fmpp" and "parserImpls.ftl". After that I want to create a new "Parser.jj" file with Apache Freemaker (I assume there are some tutorials?).

 

What I don't know:

Is it a promising plan or are there better strategies to extend the parser?

I already tried to import Flink-Table-Planner but I got many errors which might refer to a Scala-problem with Eclipse. Do I have to switch to say IntelliJ? Furthermore I'm not yet clear about how exactly I can extend the parser. Are there any manuals/tutorials to teach me adding a new SELECT-syntax? I already came across the parser extension test but it didn't give me the answers I was looking for.

 

Thanks for your help!

 

Regards,

Dominik Gröninger