Detecting columns used in DISTINCT

[sampsonsl]

New to JSQLParser. I'd like to use it to identify columns used with specific SQL operations, like DISTINCT.
Suggestion on how this is best done, or pointers to examples appreciated. Thanks.

[manticore-projects]

Greetings.

You would need to provide at least some sample SQLs to illustrate your question please.

[sampsonsl]

Thanks. What is the specific method used to check the Distinct property?

[manticore-projects]

See JAVA API: https://manticore-projects.com/JSQLParser/javadoc_snapshot.html#plainselect
Use the method getDistinct() to access the Distinct object.

[sampsonsl]

Thank you for the guidance!

[sampsonsl]

Returning to this, using getDistinct() appears to work for cases where DISTINCT is used directly in the SELECT like my two earlier examples. However, "COUNT( DISTINCT )" produces getDistinct() == null.

For example, a query like this:

SELECT COUNT(DISTINCT s_i_id) FROM stock;

In this case, I think the parser is including s_i_d under COUNT as a function. I'm not clear how to find and associate it with DISTINCT. Suggestions appreciated. Thanks!

[manticore-projects]

It's a complete different type of distinct, belonging to a function call:

SQL Text
 └─Statements: statement.select.PlainSelect
    ├─selectItems: statement.select.SelectItem
    │  └─expression: expression.Function
    │     └─ExpressionList: s_i_id
    └─Table: stock

Java API: http://217.160.215.75:8080/jsqlformatter/JSQLParser/javadoc_snapshot.html#function
Which again has the method: isDistinct().