Issues with WITH clause in SqlParser

[dnltsk]

I have the use-case to extract all table names used by complex queries. Obviously the SqlParser, respectively the QuerySpecification has trouble when the Query stars with a WITH clause.

This is how I parse the Query

import com.facebook.presto.sql.parser.SqlParser
import com.facebook.presto.sql.tree.Query
import com.facebook.presto.sql.tree.QuerySpecification

val parser = SqlParser()
val query = parser.createStatement(sql, ParsingOptions()) as Query
val body = query.queryBody as QuerySpecification
println(body.from.get())

The following query

    WITH query AS (
        select a from db1.table1
    )
    ( select * from query )

throws the Exception

java.lang.ClassCastException: class com.facebook.presto.sql.tree.Union cannot be cast to class com.facebook.presto.sql.tree.QuerySpecification (com.facebook.presto.sql.tree.Union and com.facebook.presto.sql.tree.QuerySpecification are in unnamed module of loader 'app')

Interestingly I was able to solve this by wrapping the query with a dummy SELECT *-Statement

 SELECT * FROM (
    WITH query AS (
        select a from db1.table1
    )
    ( select * from query )
 )

By that the Statement the SqlParser/QuerySpecification can successfully everything via the created TableSubquery

TableSubquery{Query{with=With{recursive=false, queries=[WithQuery{name=query, query=Query{queryBody=QuerySpecification{select=Select{distinct=false, selectItems=[a]}, from=Optional[Table{db1.table1}], where=null, groupBy=Optional.empty, having=null, orderBy=Optional.empty, offset=null, limit=null}, orderBy=Optional.empty}, columnNames=Optional.empty}]}, queryBody=TableSubquery{Query{queryBody=QuerySpecification{select=Select{distinct=false, selectItems=[*]}, from=Optional[Table{query}], where=null, groupBy=Optional.empty, having=null, orderBy=Optional.empty, offset=null, limit=null}, orderBy=Optional.empty}}, orderBy=Optional.empty}}

The Question is if it could be possible to improve the parser to it could works without the workaround.

[rubenssoto]

There is a PR to solve this issue

#17083

You can ask for community help, I have the same problem here.