Visitor
class VerifyAggregateExpressionsVisitor extends java.lang.Object implements Visitor
Modifier and Type | Field | Description |
---|---|---|
private GroupByList |
groupByList |
Constructor | Description |
---|---|
VerifyAggregateExpressionsVisitor(GroupByList groupByList) |
Modifier and Type | Method | Description |
---|---|---|
boolean |
skipChildren(Visitable node) |
Don't visit children under an aggregate, subquery or any node which
is equivalent to any of the group by expressions.
|
boolean |
stopTraversal() |
Method that is called to see
if query tree traversal should be
stopped before visiting all nodes.
|
Visitable |
visit(Visitable node) |
Verify that this expression is ok
for an aggregate query.
|
boolean |
visitChildrenFirst(Visitable node) |
Method that is called to see if
visit() should be called on
the children of node before it is called on node itself. |
private GroupByList groupByList
VerifyAggregateExpressionsVisitor(GroupByList groupByList)
public Visitable visit(Visitable node) throws StandardException
visit
in interface Visitor
node
- the node to processStandardException
- on ColumnReference not
in group by list, ValueNode or
JavaValueNode that isn't under an
aggregatepublic boolean skipChildren(Visitable node) throws StandardException
skipChildren
in interface Visitor
node
- the node to processStandardException
public boolean stopTraversal()
Visitor
stopTraversal
in interface Visitor
public boolean visitChildrenFirst(Visitable node)
Visitor
visit()
should be called on
the children of node
before it is called on node
itself.
If this method always returns true
, the visitor will walk the
tree bottom-up. If it always returns false
, the tree is visited
top-down.visitChildrenFirst
in interface Visitor
node
- the top node of a sub-tree about to be visitedtrue
if node
's children should be visited
before node
, false
otherwiseApache Derby V10.14 Internals - Copyright © 2004,2018 The Apache Software Foundation. All Rights Reserved.