Package 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	Description
final @Nullable AggregatingSelectScope	aggregatingSelectScope

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	Description
int	addGroupExpr(SqlNode expr)
List<AggregateCall>	getAggCalls()
List<Pair<RexNode,@Nullable 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

Methods inherited from interface org.apache.calcite.sql.util.SqlVisitor

visitNode

Field Details

aggregatingSelectScope

public final @Nullable AggregatingSelectScope aggregatingSelectScope

Constructor Details

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 Details

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,@Nullable String>> getPreExprs()

getAggCalls

public List<AggregateCall> getAggCalls()

getTypeFactory

public RelDataTypeFactory getTypeFactory()