org.apache.calcite.sql2rel

Class SqlToRelConverter.Blackboard

java.lang.Object

org.apache.calcite.sql2rel.SqlToRelConverter.Blackboard

All Implemented Interfaces:

SqlVisitor<RexNode>, SqlRexContext

Enclosing class:

SqlToRelConverter

protected class SqlToRelConverter.Blackboard
extends Object
implements SqlRexContext, SqlVisitor<RexNode>

Workspace for translating an individual SELECT statement (or sub-SELECT).

Field Summary

Fields

Modifier and Type	Field and Description
RelNode	root
SqlValidatorScope	scope Collection of RelNode objects which correspond to a SELECT statement.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SqlToRelConverter.Blackboard(SqlValidatorScope scope, Map<String,RexNode> nameToNodeMap) Creates a Blackboard.

Method Summary

Methods

Modifier and Type	Method and Description
RexNode	convertExpression(SqlNode expr) Converts an expression from SqlNode to RexNode format.
RexNode	convertInterval(SqlIntervalQualifier intervalQualifier)
RexNode	convertLiteral(SqlLiteral literal) Converts a literal.
RexNode	convertSortExpression(SqlNode expr, Set<SqlKind> flags) Converts an item in an ORDER BY clause, extracting DESC, NULLS LAST and NULLS FIRST flags first.
void	flatten(List<RelNode> rels, int systemFieldCount, int[] start, List<Pair<RelNode,Integer>> relOffsetList)
List<SqlMonotonicity>	getColumnMonotonicities()
DefaultValueFactory	getDefaultValueFactory() Returns the factory which supplies default values for INSERT, UPDATE, and NEW.
int	getGroupCount() If the operator call occurs in an aggregate query, returns the number of columns in the GROUP BY clause.
RexBuilder	getRexBuilder() Returns the RexBuilder to use to create RexNode objects.
RexRangeRef	getSubqueryExpr(SqlCall call) Returns the expression used to access a given IN or EXISTS sub-query.
RelDataTypeFactory	getTypeFactory() Returns the type factory.
SqlValidator	getValidator() Returns the validator.
RexNode	register(RelNode rel, JoinRelType joinType)
RexNode	register(RelNode rel, JoinRelType joinType, List<RexNode> leftKeys) Registers a relational expression.
void	setDataset(String datasetName) Notifies this Blackboard that the root just set using setRoot(RelNode, boolean) was derived using dataset substitution.
void	setRoot(RelNode root, boolean leaf) Sets a new root relational expression, as the translation process backs its way further up the tree.
RexNode	visit(SqlCall call) Visits a call to a SqlOperator.
RexNode	visit(SqlDataTypeSpec type) Visits a datatype specification.
RexNode	visit(SqlDynamicParam param) Visits a dynamic parameter.
RexNode	visit(SqlIdentifier id) Visits an identifier.
RexNode	visit(SqlIntervalQualifier intervalQualifier) Visits an interval qualifier
RexNode	visit(SqlLiteral literal) Visits a literal.
RexNode	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

scope

public final SqlValidatorScope scope

Collection of RelNode objects which correspond to a SELECT statement.

root

public RelNode root

Constructor Detail

SqlToRelConverter.Blackboard

protected SqlToRelConverter.Blackboard(SqlValidatorScope scope,
                            Map<String,RexNode> nameToNodeMap)

Creates a Blackboard.

Parameters:

scope - Name-resolution scope for expressions validated within this query. Can be null if this Blackboard is for a leaf node, say

nameToNodeMap - Map which translates the expression to map a given parameter into, if translating expressions; null otherwise

Method Detail

register

public RexNode register(RelNode rel,
               JoinRelType joinType)

register

public RexNode register(RelNode rel,
               JoinRelType joinType,
               List<RexNode> leftKeys)

Registers a relational expression.

Parameters:

rel - Relational expression

joinType - Join type

leftKeys - LHS of IN clause, or null for expressions other than IN

Returns:

Expression with which to refer to the row (or partial row) coming from this relational expression's side of the join

setRoot

public void setRoot(RelNode root,
           boolean leaf)

Sets a new root relational expression, as the translation process backs its way further up the tree.

Parameters:

root - New root relational expression

leaf - Whether the relational expression is a leaf, that is, derived from an atomic relational expression such as a table name in the from clause, or the projection on top of a select-subquery. In particular, relational expressions derived from JOIN operators are not leaves, but set expressions are.

setDataset

public void setDataset(String datasetName)

Notifies this Blackboard that the root just set using setRoot(RelNode, boolean) was derived using dataset substitution.

The default implementation is not interested in such notifications, and does nothing.

Parameters:

datasetName - Dataset name

flatten

public void flatten(List<RelNode> rels,
           int systemFieldCount,
           int[] start,
           List<Pair<RelNode,Integer>> relOffsetList)

convertExpression

public RexNode convertExpression(SqlNode expr)

Description copied from interface: SqlRexContext

Converts an expression from SqlNode to RexNode format.

Specified by:

convertExpression in interface SqlRexContext

Parameters:

expr - Expression to translate

Returns:

Converted expression

convertSortExpression

public RexNode convertSortExpression(SqlNode expr,
                            Set<SqlKind> flags)

Converts an item in an ORDER BY clause, extracting DESC, NULLS LAST and NULLS FIRST flags first.

getGroupCount

public int getGroupCount()

Description copied from interface: SqlRexContext

If the operator call occurs in an aggregate query, returns the number of columns in the GROUP BY clause. For example, for "SELECT count(*) FROM emp GROUP BY deptno, gender", returns 2. If the operator call occurs in window aggregate query, then returns 1 if the window is guaranteed to be non-empty, or 0 if the window might be empty.

Returns 0 if the query is implicitly "GROUP BY ()" because of an aggregate expression. For example, "SELECT sum(sal) FROM emp".

Returns -1 if the query is not an aggregate query.

Specified by:

getGroupCount in interface SqlRexContext

Returns:

0 if the query is implicitly GROUP BY (), -1 if the query is not and aggregate query

See Also:

SqlOperatorBinding.getGroupCount()

getRexBuilder

public RexBuilder getRexBuilder()

Description copied from interface: SqlRexContext

Returns the RexBuilder to use to create RexNode objects.

Specified by:

getRexBuilder in interface SqlRexContext

getSubqueryExpr

public RexRangeRef getSubqueryExpr(SqlCall call)

Description copied from interface: SqlRexContext

Returns the expression used to access a given IN or EXISTS sub-query.

Specified by:

getSubqueryExpr in interface SqlRexContext

Parameters:

call - IN or EXISTS expression

Returns:

Expression used to access current row of sub-query

getTypeFactory

public RelDataTypeFactory getTypeFactory()

Description copied from interface: SqlRexContext

Returns the type factory.

Specified by:

getTypeFactory in interface SqlRexContext

getDefaultValueFactory

public DefaultValueFactory getDefaultValueFactory()

Description copied from interface: SqlRexContext

Returns the factory which supplies default values for INSERT, UPDATE, and NEW.

Specified by:

getDefaultValueFactory in interface SqlRexContext

getValidator

public SqlValidator getValidator()

Description copied from interface: SqlRexContext

Returns the validator.

Specified by:

getValidator in interface SqlRexContext

convertLiteral

public RexNode convertLiteral(SqlLiteral literal)

Description copied from interface: SqlRexContext

Converts a literal.

Specified by:

convertLiteral in interface SqlRexContext

convertInterval

public RexNode convertInterval(SqlIntervalQualifier intervalQualifier)

visit

public RexNode visit(SqlLiteral literal)

Description copied from interface: SqlVisitor

Visits a literal.

Specified by:

visit in interface SqlVisitor<RexNode>

Parameters:

literal - Literal

See Also:

SqlLiteral.accept(SqlVisitor)

visit

public RexNode visit(SqlCall call)

Description copied from interface: SqlVisitor

Visits a call to a SqlOperator.

Specified by:

visit in interface SqlVisitor<RexNode>

Parameters:

call - Call

See Also:

SqlCall.accept(SqlVisitor)

visit

public RexNode visit(SqlNodeList nodeList)

Description copied from interface: SqlVisitor

Visits a list of SqlNode objects.

Specified by:

visit in interface SqlVisitor<RexNode>

Parameters:

nodeList - list of nodes

See Also:

SqlNodeList.accept(SqlVisitor)

visit

public RexNode visit(SqlIdentifier id)

Description copied from interface: SqlVisitor

Visits an identifier.

Specified by:

visit in interface SqlVisitor<RexNode>

Parameters:

id - identifier

See Also:

SqlIdentifier.accept(SqlVisitor)

visit

public RexNode visit(SqlDataTypeSpec type)

Description copied from interface: SqlVisitor

Visits a datatype specification.

Specified by:

visit in interface SqlVisitor<RexNode>

Parameters:

type - datatype specification

See Also:

SqlDataTypeSpec.accept(SqlVisitor)

visit

public RexNode visit(SqlDynamicParam param)

Description copied from interface: SqlVisitor

Visits a dynamic parameter.

Specified by:

visit in interface SqlVisitor<RexNode>

Parameters:

param - Dynamic parameter

See Also:

SqlDynamicParam.accept(SqlVisitor)

visit

public RexNode visit(SqlIntervalQualifier intervalQualifier)

Description copied from interface: SqlVisitor

Visits an interval qualifier

Specified by:

visit in interface SqlVisitor<RexNode>

Parameters:

intervalQualifier - Interval qualifier

See Also:

SqlIntervalQualifier.accept(SqlVisitor)

getColumnMonotonicities

public List<SqlMonotonicity> getColumnMonotonicities()