net.sf.saffron.rex
Class RexInputRef

java.lang.Object
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  +--net.sf.saffron.rex.RexNode
        |
        +--net.sf.saffron.rex.RexVariable
              |
              +--net.sf.saffron.rex.RexInputRef

public class RexInputRef

extends RexVariable

Variable which references a field of an input relational expression.

Fields of the input are 0-based. If there is more than one input, they are numbered consecutively. For example, if the inputs to a join are

• Input #0: EMP(EMPNO, ENAME, DEPTNO) and
• Input #1: DEPT(DEPTNO AS DEPTNO2, DNAME)

then the fields are:

• Field #0: EMPNO
• Field #1: ENAME
• Field #2: DEPTNO (from EMP)
• Field #3: DEPTNO2 (from DEPT)
• Field #4: DNAME

So RexInputRef(3,Integer) is the correct reference for the field DEPTNO2.

Since:

Nov 24, 2003

Version:

$Id: $

Author:

jhyde

Field Summary

int

index

Fields inherited from class net.sf.saffron.rex.RexVariable

name, type

Fields inherited from class net.sf.saffron.rex.RexNode

digest

Constructor Summary

RexInputRef(int index, SaffronType type)
Creates an input variable.

Method Summary

Object

clone()

Methods inherited from class net.sf.saffron.rex.RexVariable

getName, getType

Methods inherited from class net.sf.saffron.rex.RexNode

getKind, isA, isAlwaysTrue, toString

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

index

public final int index

Constructor Detail

RexInputRef

public RexInputRef(int index,
                   SaffronType type)

Creates an input variable.

Parameters:

index - Index of the field in the underlying rowtype

type - Type of the column

Method Detail

clone

public Object clone()

Specified by:

clone in class RexNode