[CALCITE-3261] Make JDBC output column labels more human readable

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: core, jdbc-adapter
• Assignee: Xiaoguang Zhang
• Reporter: Xiaoguang zhang
• Created: 18/Aug/19 02:21
• Updated: 20/Aug/19 18:10

Description

After implementing the missing `print(ResultSet)` method from the examples in Calcite [tutorial|https://calcite.apache.org/docs/index.html], I found that the output field names are incorrect:

[deptno, EXPR$1]
[1, 1]
[2, 2]

The field name `EXPR$1` can be improved to be more human readable like MySQL client:

+--------+--------------+
| deptno | min(e.empid) |
+--------+--------------+
|      1 |            1 |
|      2 |            2 |
+--------+--------------+

 

PS: the sql statement generating the above outputs:

select d.deptno, min(e.empid) from hr.emps as e join hr.depts as d on e.deptno = d.deptno group by d.deptno having count(*) > 1