org.apache.calcite.rex

Class RexInputRef

java.lang.Object

org.apache.calcite.rex.RexNode

org.apache.calcite.rex.RexVariable

org.apache.calcite.rex.RexSlot

org.apache.calcite.rex.RexInputRef

public class RexInputRef
extends RexSlot

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.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.calcite.rex.RexSlot

RexSlot.SelfPopulatingList

Field Summary

Fields inherited from class org.apache.calcite.rex.RexSlot

index

Fields inherited from class org.apache.calcite.rex.RexVariable

name, type

Fields inherited from class org.apache.calcite.rex.RexNode

digest

Constructor Summary

Constructors

Constructor and Description
RexInputRef(int index, RelDataType type) Creates an input variable.

Method Summary

Methods

Modifier and Type	Method and Description
<R> R	accept(RexVisitor<R> visitor) Accepts a visitor, dispatching to the right overloaded visitXxx method.
static String	createName(int index) Creates a name for an input reference, of the form "$index".
boolean	equals(Object obj)
SqlKind	getKind() Returns the kind of node this is.
int	hashCode()
static RexInputRef	of(int index, List<RelDataTypeField> fields) Creates a reference to a given field in a list of fields.
static RexInputRef	of(int index, RelDataType rowType) Creates a reference to a given field in a row type.
static Pair<RexNode,String>	of2(int index, List<RelDataTypeField> fields) Creates a reference to a given field in a list of fields.

Methods inherited from class org.apache.calcite.rex.RexSlot

getIndex

Methods inherited from class org.apache.calcite.rex.RexVariable

getName, getType

Methods inherited from class org.apache.calcite.rex.RexNode

isA, isA, isAlwaysFalse, isAlwaysTrue, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

RexInputRef

public RexInputRef(int index,
           RelDataType type)

Creates an input variable.

Parameters:

index - Index of the field in the underlying row-type

type - Type of the column

Method Detail

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

of

public static RexInputRef of(int index,
             RelDataType rowType)

Creates a reference to a given field in a row type.

of

public static RexInputRef of(int index,
             List<RelDataTypeField> fields)

Creates a reference to a given field in a list of fields.

of2

public static Pair<RexNode,String> of2(int index,
                       List<RelDataTypeField> fields)

Creates a reference to a given field in a list of fields.

getKind

public SqlKind getKind()

Description copied from class: RexNode

Returns the kind of node this is.

Overrides:

getKind in class RexNode

Returns:

Node kind, never null

accept

public <R> R accept(RexVisitor<R> visitor)

Description copied from class: RexNode

Accepts a visitor, dispatching to the right overloaded visitXxx method.

Also see RexUtil.apply(RexVisitor, java.util.List, RexNode), which applies a visitor to several expressions simultaneously.

Specified by:

accept in class RexNode

createName

public static String createName(int index)

Creates a name for an input reference, of the form "$index". If the index is low, uses a cache of common names, to reduce gc.