Apache Derby Database Engine and Embedded JDBC Driver 10.17.1.0 · org.apache.derby.impl.sql.compile.WindowFunctionNode

Modifier and Type	Field and Description
private ResultColumn	generatedRC
private ColumnReference	generatedRef
private WindowNode	window

Access	Constructor and Description
pack-priv	WindowFunctionNode(ValueNode operand (null for now) op, String operator functionName, WindowNode window node (definition or reference) w, ContextManager context manager cm)

Method Summary

Modifier and Type	Method and Description
pack-priv ValueNode	bindExpression(FromList The FROM list for the query this expression is in, for binding columns. fromList, SubqueryList The subquery list being built as we find SubqueryNodes subqueryList, List<AggregateNode> The aggregate list being built as we find AggregateNodes aggregates) Overrides org.apache.derby.impl.sql.compile.UnaryOperatorNode.bindExpression. ValueNode override.
pack-priv boolean	constantExpression(PredicateList whereClause) Overrides org.apache.derby.impl.sql.compile.UnaryOperatorNode.constantExpression. ValueNode override.
private WindowDefinitionNode	Returns: if name matches a defined window (in windows), return the definition of that window, else null. definedWindow(WindowList windows, String name)
pack-priv ColumnReference	Returns: the column reference getGeneratedRef() Get the generated ColumnReference to this window function after the parent called replaceCallsWithColumnReferences().
pack-priv ValueNode	Returns: the value node getNewNullResultExpression() Get the null result expression column.
pack-priv WindowNode	Returns: window associated with this window function getWindow()
public boolean	isConstantExpression() Overrides org.apache.derby.impl.sql.compile.UnaryOperatorNode.isConstantExpression. ValueNode override.
public void	printSubNodes(int The depth of this node in the tree depth) Overrides org.apache.derby.impl.sql.compile.UnaryOperatorNode.printSubNodes. QueryTreeNode override.
pack-priv ValueNode	Returns: ValueNode The (potentially) modified tree. replaceCallsWithColumnReferences(ResultColumnList The RCL to append to. rcl, int The tableNumber for the new ColumnReference tableNumber) Replace window function calls in the expression tree with a ColumnReference to that window function, append the aggregate to the supplied RCL (assumed to be from the child ResultSetNode) and return the ColumnReference.
pack-priv void	setWindow(WindowDefinitionNode window definition wdn) Set window associated with this window function call.

Inherited from org.apache.derby.impl.sql.compile.UnaryOperatorNode:: acceptChildren addXmlOpMethodParams bindOperand bindParameter categorize generateExpression getOperand getOperatorString getOrderableVariantType getParameterOperand getReceiverInterfaceName isEquivalent isSameNodeKind preprocess remapColumnReferencesToExpressions setMethodName setOperator toString

generatedRC	back to summary
private ResultColumn generatedRC

generatedRef	back to summary
private ColumnReference generatedRef

window	back to summary
private WindowNode window

WindowFunctionNode	back to summary
pack-priv WindowFunctionNode(ValueNode op, String functionName, WindowNode w, ContextManager cm) throws StandardException Parameters op:ValueNode operand (null for now) functionName:String operator w:WindowNode window node (definition or reference) cm:ContextManager context manager

Method Detail

bindExpression back to summary

bindExpression	back to summary
pack-priv ValueNode bindExpression(FromList fromList, SubqueryList subqueryList, List<AggregateNode> aggregates) throws StandardException Overrides org.apache.derby.impl.sql.compile.UnaryOperatorNode.bindExpression. ValueNode override. Parameters fromList:FromList Doc from org.apache.derby.impl.sql.compile.UnaryOperatorNode.bindExpression. The FROM list for the query this expression is in, for binding columns. subqueryList:SubqueryList Doc from org.apache.derby.impl.sql.compile.UnaryOperatorNode.bindExpression. The subquery list being built as we find SubqueryNodes aggregates:List<AggregateNode> Doc from org.apache.derby.impl.sql.compile.UnaryOperatorNode.bindExpression. The aggregate list being built as we find AggregateNodes Returns:ValueNode Doc from org.apache.derby.impl.sql.compile.UnaryOperatorNode.bindExpression. The new top of the expression tree. Annotations @Override Exceptions StandardException: Doc from org.apache.derby.impl.sql.compile.UnaryOperatorNode.bindExpression. Thrown on error See Also `ValueNode#bindExpression`

pack-priv ValueNode bindExpression(FromList fromList, SubqueryList subqueryList, List<AggregateNode> aggregates) throws StandardException

Overrides org.apache.derby.impl.sql.compile.UnaryOperatorNode.bindExpression.

ValueNode override.

Parameters

fromList:FromList

Doc from org.apache.derby.impl.sql.compile.UnaryOperatorNode.bindExpression.

The FROM list for the query this expression is in, for binding columns.

subqueryList:SubqueryList

Doc from org.apache.derby.impl.sql.compile.UnaryOperatorNode.bindExpression.

The subquery list being built as we find SubqueryNodes

aggregates:List<AggregateNode>

Doc from org.apache.derby.impl.sql.compile.UnaryOperatorNode.bindExpression.

The aggregate list being built as we find AggregateNodes

Returns:ValueNode

Doc from org.apache.derby.impl.sql.compile.UnaryOperatorNode.bindExpression.

The new top of the expression tree.

Annotations

@Override

Exceptions

StandardException:

Doc from org.apache.derby.impl.sql.compile.UnaryOperatorNode.bindExpression.

Thrown on error

See Also

ValueNode#bindExpression

constantExpression back to summary

constantExpression	back to summary
pack-priv boolean constantExpression(PredicateList whereClause) Overrides org.apache.derby.impl.sql.compile.UnaryOperatorNode.constantExpression. ValueNode override. Returns:boolean Doc from org.apache.derby.impl.sql.compile.ValueNode.constantExpression. True means this expression tree represents a constant value. Annotations @Override See Also `ValueNode#isConstantExpression`

pack-priv boolean constantExpression(PredicateList whereClause)

Overrides org.apache.derby.impl.sql.compile.UnaryOperatorNode.constantExpression.

ValueNode override.

Returns:boolean

Doc from org.apache.derby.impl.sql.compile.ValueNode.constantExpression.

True means this expression tree represents a constant value.

Annotations

@Override

See Also

ValueNode#isConstantExpression

definedWindow	back to summary
private WindowDefinitionNode definedWindow(WindowList windows, String name) Returns:WindowDefinitionNode if name matches a defined window (in windows), return the definition of that window, else null.

getGeneratedRef back to summary

getGeneratedRef	back to summary
pack-priv ColumnReference getGeneratedRef() Get the generated ColumnReference to this window function after the parent called replaceCallsWithColumnReferences(). There are cases where this will not have been done because the tree has been re-written to eliminate the window function, e.g. for this query: `SELECT * FROM t WHERE EXISTS (SELECT ROW_NUMBER() OVER () FROM t)` in which case the top PRN of the subquery sitting over a WindowResultSetNode just contains a RC which is boolean constant `true`. This means that the replaceCallsWithColumnReferences will not have been called for `this`, so the returned `generatedRef` is null. Returns:ColumnReference the column reference

pack-priv ColumnReference getGeneratedRef()

Get the generated ColumnReference to this window function after the parent called replaceCallsWithColumnReferences().

There are cases where this will not have been done because the tree has been re-written to eliminate the window function, e.g. for this query:

    SELECT * FROM t WHERE EXISTS
          (SELECT ROW_NUMBER() OVER () FROM t)

in which case the top PRN of the subquery sitting over a WindowResultSetNode just contains a RC which is boolean constant true. This means that the replaceCallsWithColumnReferences will not have been called for this, so the returned generatedRef is null.

Returns:ColumnReference: the column reference

getNewNullResultExpression	back to summary
pack-priv ValueNode getNewNullResultExpression() throws StandardException Get the null result expression column. Returns:ValueNode the value node Exceptions StandardException: on error

getNewNullResultExpression

back to summary

pack-priv ValueNode getNewNullResultExpression() throws StandardException

Get the null result expression column.

Returns:ValueNode

the value node

Exceptions

StandardException:: on error

getWindow	back to summary
pack-priv WindowNode getWindow() Returns:WindowNode window associated with this window function

isConstantExpression back to summary

isConstantExpression	back to summary
public boolean isConstantExpression() Overrides org.apache.derby.impl.sql.compile.UnaryOperatorNode.isConstantExpression. ValueNode override. Returns:boolean Doc from org.apache.derby.impl.sql.compile.UnaryOperatorNode.isConstantExpression. Whether or not this expression tree represents a constant expression. Annotations @Override See Also `ValueNode#isConstantExpression`

public boolean isConstantExpression()

Overrides org.apache.derby.impl.sql.compile.UnaryOperatorNode.isConstantExpression.

ValueNode override.

Returns:boolean

Doc from org.apache.derby.impl.sql.compile.UnaryOperatorNode.isConstantExpression.

Whether or not this expression tree represents a constant expression.

Annotations

@Override

See Also

ValueNode#isConstantExpression

printSubNodes back to summary

printSubNodes	back to summary
public void printSubNodes(int depth) Overrides org.apache.derby.impl.sql.compile.UnaryOperatorNode.printSubNodes. QueryTreeNode override. Parameters depth:int Doc from org.apache.derby.impl.sql.compile.UnaryOperatorNode.printSubNodes. The depth of this node in the tree Annotations @Override See Also `QueryTreeNode#printSubNodes`

public void printSubNodes(int depth)

Overrides org.apache.derby.impl.sql.compile.UnaryOperatorNode.printSubNodes.

QueryTreeNode override.

Parameters

depth:int

Doc from org.apache.derby.impl.sql.compile.UnaryOperatorNode.printSubNodes.

The depth of this node in the tree

Annotations

@Override

See Also

QueryTreeNode#printSubNodes

replaceCallsWithColumnReferences	back to summary
pack-priv ValueNode replaceCallsWithColumnReferences(ResultColumnList rcl, int tableNumber) throws StandardException Replace window function calls in the expression tree with a ColumnReference to that window function, append the aggregate to the supplied RCL (assumed to be from the child ResultSetNode) and return the ColumnReference. Parameters rcl:ResultColumnList The RCL to append to. tableNumber:int The tableNumber for the new ColumnReference Returns:ValueNode ValueNode The (potentially) modified tree. Exceptions StandardException: Thrown on error

replaceCallsWithColumnReferences

back to summary

pack-priv ValueNode replaceCallsWithColumnReferences(ResultColumnList rcl, int tableNumber) throws StandardException

Replace window function calls in the expression tree with a ColumnReference to that window function, append the aggregate to the supplied RCL (assumed to be from the child ResultSetNode) and return the ColumnReference.

Parameters

rcl:ResultColumnList: The RCL to append to.
tableNumber:int: The tableNumber for the new ColumnReference

Returns:ValueNode

ValueNode The (potentially) modified tree.

Exceptions

StandardException:: Thrown on error

setWindow	back to summary
pack-priv void setWindow(WindowDefinitionNode wdn) Set window associated with this window function call. Parameters wdn:WindowDefinitionNode window definition

setWindow

back to summary

pack-priv void setWindow(WindowDefinitionNode wdn)

Set window associated with this window function call.

Parameters

wdn:WindowDefinitionNode: window definition

public abstract Class WindowFunctionNode

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