extra column in DatabaseMetaData.getColumns() with group by in view

[Kathey Marsden]

I have user report that DatabaseMetaData.getColumns() on a view with a 
group by returns an extra column.  Attached is the reproduction.  Run 
the create.sql script and then run the program ViewTest. The bug is a 
regression in 10.3 (Latest on the 10.1 and 10.2 branch works fine and it 
still exists in trunk.)

This sounds very familiar so I was wondering if there is already an 
issue filed.  The closest thing I could find was 
https://issues.apache.org/jira/browse/DERBY-3141 which was regarding 
ResultSetMetaData and an order by.  I haven't checked yet to see if the 
ResultSetMetaData is also wrong.

Kathey


/*
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import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;


public class ViewTest {

        public static void main(String[] args) throws ClassNotFoundException, 
SQLException {
        Class.forName("org.apache.derby.jdbc.EmbeddedDriver");
        Connection connection = 
DriverManager.getConnection("jdbc:derby:wombat");
        
        DatabaseMetaData metaData = connection.getMetaData();
        ResultSet columns = metaData.getColumns(null, null, "V", null);
        while (columns.next()) {
                String name = columns.getString("COLUMN_NAME");
                String pos = columns.getString("ORDINAL_POSITION");
                String type = columns.getString("TYPE_NAME");
                System.out.println("name = " + name + ", pos = " + pos + ", 
type = " + type);
        }
        
        columns.close();
        connection.close();
        }
}
connect 'jdbc:derby:wombat;create=true';
create table A (id integer, data varchar(20), data2 integer);
create view V (data, num) as select data, data2 + 2 from A group by data, data2;
insert into A values (3, 'G', 5), (23, 'G', 4), (5, 'F', 1), (2, 'H', 4), (1, 
'F', 5);