| java.lang.Object
 org.apache.derby.impl.sql.compile.VerifyAggregateExpressionsVisitor
| VerifyAggregateExpressionsVisitor | | public class VerifyAggregateExpressionsVisitor implements Visitor(Code) | | If a RCL (SELECT list) contains an aggregate, then we must verify
that the RCL (SELECT list) is valid.
For ungrouped queries,
the RCL must be composed entirely of valid aggregate expressions -
in this case, no column references outside of an aggregate.
For grouped aggregates,
the RCL must be composed of grouping columns or valid aggregate
expressions - in this case, the only column references allowed outside of
an aggregate are grouping columns.
author:
jamie, from code written by jerry |
| Method Summary | |
| public 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. | | public boolean | stopTraversal()
| | public Visitable | visit(Visitable node)
Verify that this expression is ok
for an aggregate query. |
| VerifyAggregateExpressionsVisitor | | public VerifyAggregateExpressionsVisitor(GroupByList groupByList)(Code) | | |
| skipChildren | | public boolean skipChildren(Visitable node) throws StandardException(Code) | | Don't visit children under an aggregate, subquery or any node which
is equivalent to any of the group by expressions.
Parameters:
node - the node to process true/false
throws:
StandardException - |
| stopTraversal | | public boolean stopTraversal()(Code) | | |
| visit | | public Visitable visit(Visitable node) throws StandardException(Code) | | Verify that this expression is ok
for an aggregate query.
Parameters:
node - the node to process me
exception:
StandardException - on ColumnReference notin group by list, ValueNode or JavaValueNode that isn't under anaggregate |
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