Re: I have some questions about the offset of the RexRangeRef

[Stamatis Zampetakis <za...@gmail.com>]

The example with RexInputRef(5) is mentioned in the Javadoc of RexRangeRef
[1] and it looks like a typo. As Julian said, it should be RexInputRef(4)
and the type should probably be VARCHAR.

[1]
https://github.com/apache/calcite/blob/8983e7e82ef65c3a72f06305a676cc2998bf72d6/core/src/main/java/org/apache/calcite/rex/RexRangeRef.java#L40

On Thu, Dec 30, 2021 at 10:18 AM Julian Hyde <jh...@gmail.com> wrote:

> Column ordinals are as follows:
>
> 0 EMP.EMPNO
> 1 EMP.ENAME
> 2 EMP.DEPTNO
> 3 DEPT.DEPTNO2
> 4 DEPT.DNAME
>
> So I would expect Calcite to return RexInputRef(4, Integer) for DNAME.
>
> If you’re seeing RexInputRef(5) there is something strange going on in
> your environment (e.g. EMP has more columns than you think).
>
> Julian
>
>
> > On Dec 29, 2021, at 11:22 PM, 董剑辉 <mu...@gmail.com> wrote:
> >
> > I see the following java doc in org.apache.calcite.rex.RexRangeRef, and I
> > want to ask why return  RexInputRef(5,Integer) not RexInputRef(4,Integer)
> > when create a reference to the DNAME field?
> > "Reference to a range of columns.
> > This construct is used only during the process of translating a SQL tree
> to
> > a rel/rex tree. Regular rex trees do not contain this construct.
> > While translating a join of EMP(EMPNO, ENAME, DEPTNO) to DEPT(DEPTNO2,
> > DNAME) we create RexRangeRef(DeptType,3) to represent the pair of columns
> > (DEPTNO2, DNAME) which came from DEPT. The type has 2 columns, and
> > therefore the range represents columns {3, 4} of the input.
> > Suppose we later create a reference to the DNAME field of this
> RexRangeRef;
> > it will return a RexInputRef(5,Integer), and the RexRangeRef will
> > disappear."
> > Thank you =)
>
>