Package com.mckoi.database

Class QueryPlan.FunctionalSelectNode

java.lang.Object

com.mckoi.database.QueryPlan.SingleQueryPlanNode

com.mckoi.database.QueryPlan.FunctionalSelectNode

All Implemented Interfaces:

QueryPlanNode, java.io.Serializable, java.lang.Cloneable

Enclosing class:

QueryPlan

public static class QueryPlan.FunctionalSelectNode
extends QueryPlan.SingleQueryPlanNode

The node for performing a functional select operation on the child node. Some examples of this type of query are; CONCAT(a, ' ', b) > 'abba boh' TONUMBER(DATEFORMAT(a, 'yyyy')) > 2001 LOWER(a) < 'ook' The reason this is a separate node is because it is possible to exploit a functional indexes on a table with this node.

The given expression MUST be of the form; 'function_expression' 'operator' 'constant'

See Also:

Serialized Form

Field Summary

Fields inherited from class com.mckoi.database.QueryPlan.SingleQueryPlanNode

child

Constructor Summary

Constructors

Constructor	Description
FunctionalSelectNode(QueryPlanNode child, Expression exp)

Method Summary

Modifier and Type	Method	Description
java.lang.Object	clone()	Deep clone.
java.util.ArrayList	discoverCorrelatedVariables(int level, java.util.ArrayList list)	Default implementation that discovers correlated variables for the given offset level.
java.util.ArrayList	discoverTableNames(java.util.ArrayList list)	Default implementation delegates responsibility to child.
Table	evaluate(QueryContext context)	Evaluates the node and returns the result as a Table.

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from class com.mckoi.database.QueryPlan.SingleQueryPlanNode

child, debugString, titleString

Constructor Detail

FunctionalSelectNode

public FunctionalSelectNode(QueryPlanNode child,
                            Expression exp)

Method Detail

evaluate

public Table evaluate(QueryContext context)

Description copied from interface: QueryPlanNode

Evaluates the node and returns the result as a Table. The VariableResolver resolves any outer variables

discoverTableNames

public java.util.ArrayList discoverTableNames(java.util.ArrayList list)

Description copied from class: QueryPlan.SingleQueryPlanNode

Default implementation delegates responsibility to child.

Specified by:

discoverTableNames in interface QueryPlanNode

Overrides:

discoverTableNames in class QueryPlan.SingleQueryPlanNode

discoverCorrelatedVariables

public java.util.ArrayList discoverCorrelatedVariables(int level,
                                                       java.util.ArrayList list)

Description copied from class: QueryPlan.SingleQueryPlanNode

Default implementation that discovers correlated variables for the given offset level.

Specified by:

discoverCorrelatedVariables in interface QueryPlanNode

Overrides:

discoverCorrelatedVariables in class QueryPlan.SingleQueryPlanNode

clone

public java.lang.Object clone()
                       throws java.lang.CloneNotSupportedException

Description copied from class: QueryPlan.SingleQueryPlanNode

Deep clone.

Specified by:

clone in interface QueryPlanNode

Overrides:

clone in class QueryPlan.SingleQueryPlanNode

Throws:

java.lang.CloneNotSupportedException