org.apache.calcite.sql2rel

Class SqlToRelConverter.AggConverter

java.lang.Object

org.apache.calcite.sql2rel.SqlToRelConverter.AggConverter

All Implemented Interfaces:

SqlVisitor<Void>

Enclosing class:

SqlToRelConverter

protected class SqlToRelConverter.AggConverter
extends Object
implements SqlVisitor<Void>

Converts expressions to aggregates.

Consider the expression

SELECT deptno, SUM(2 * sal) FROM emp GROUP BY deptno

Then:

• groupExprs = {SqlIdentifier(deptno)}
• convertedInputExprs = {RexInputRef(deptno), 2 * RefInputRef(sal)}
• inputRefs = {RefInputRef(#0), RexInputRef(#1)}
• aggCalls = {AggCall(SUM, {1})}

Field Summary

Fields

Modifier and Type	Field and Description
@Nullable AggregatingSelectScope	aggregatingSelectScope

Constructor Summary

Constructors

Constructor and Description
AggConverter(SqlToRelConverter.Blackboard bb, SqlSelect select) Creates an AggConverter.

Method Summary

Modifier and Type	Method and Description
int	addGroupExpr(SqlNode expr)
List<AggregateCall>	getAggCalls()
List<Pair<RexNode,String>>	getPreExprs()
RelDataTypeFactory	getTypeFactory()
@Nullable RexNode	lookupAggregates(SqlCall call)
int	lookupGroupExpr(SqlNode expr) If an expression is structurally identical to one of the group-by expressions, returns a reference to the expression, otherwise returns null.
Void	visit(SqlCall call) Visits a call to a SqlOperator.
Void	visit(SqlDataTypeSpec type) Visits a datatype specification.
Void	visit(SqlDynamicParam param) Visits a dynamic parameter.
Void	visit(SqlIdentifier id) Visits an identifier.
Void	visit(SqlIntervalQualifier intervalQualifier) Visits an interval qualifier.
Void	visit(SqlLiteral lit) Visits a literal.
Void	visit(SqlNodeList nodeList) Visits a list of SqlNode objects.

Methods inherited from class java.lang.Object

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

Field Detail

aggregatingSelectScope

public final @Nullable AggregatingSelectScope aggregatingSelectScope

Constructor Detail

AggConverter

public AggConverter(SqlToRelConverter.Blackboard bb,
                    SqlSelect select)

Creates an AggConverter.

The select parameter provides enough context to name aggregate calls which are top-level select list items.

Parameters:

bb - Blackboard

select - Query being translated; provides context to give

Method Detail

addGroupExpr

public int addGroupExpr(SqlNode expr)

visit

public Void visit(SqlIdentifier id)

Description copied from interface: SqlVisitor

Visits an identifier.

Specified by:

visit in interface SqlVisitor<Void>

Parameters:

id - identifier

See Also:

SqlIdentifier.accept(SqlVisitor)

visit

public Void visit(SqlNodeList nodeList)

Description copied from interface: SqlVisitor

Visits a list of SqlNode objects.

Specified by:

visit in interface SqlVisitor<Void>

Parameters:

nodeList - list of nodes

See Also:

SqlNodeList.accept(SqlVisitor)

visit

public Void visit(SqlLiteral lit)

Description copied from interface: SqlVisitor

Visits a literal.

Specified by:

visit in interface SqlVisitor<Void>

Parameters:

lit - Literal

See Also:

SqlLiteral.accept(SqlVisitor)

visit

public Void visit(SqlDataTypeSpec type)

Description copied from interface: SqlVisitor

Visits a datatype specification.

Specified by:

visit in interface SqlVisitor<Void>

Parameters:

type - datatype specification

See Also:

SqlDataTypeSpec.accept(SqlVisitor)

visit

public Void visit(SqlDynamicParam param)

Description copied from interface: SqlVisitor

Visits a dynamic parameter.

Specified by:

visit in interface SqlVisitor<Void>

Parameters:

param - Dynamic parameter

See Also:

SqlDynamicParam.accept(SqlVisitor)

visit

public Void visit(SqlIntervalQualifier intervalQualifier)

Description copied from interface: SqlVisitor

Visits an interval qualifier.

Specified by:

visit in interface SqlVisitor<Void>

Parameters:

intervalQualifier - Interval qualifier

See Also:

SqlIntervalQualifier.accept(SqlVisitor)

visit

public Void visit(SqlCall call)

Description copied from interface: SqlVisitor

Visits a call to a SqlOperator.

Specified by:

visit in interface SqlVisitor<Void>

Parameters:

call - Call

See Also:

SqlCall.accept(SqlVisitor)

lookupGroupExpr

public int lookupGroupExpr(SqlNode expr)

If an expression is structurally identical to one of the group-by expressions, returns a reference to the expression, otherwise returns null.

lookupAggregates

public @Nullable RexNode lookupAggregates(SqlCall call)

getPreExprs

public List<Pair<RexNode,String>> getPreExprs()

getAggCalls

public List<AggregateCall> getAggCalls()

getTypeFactory

public RelDataTypeFactory getTypeFactory()