com.mckoi.database

Class QueryPlan.SubsetNode

java.lang.Object

com.mckoi.database.QueryPlan.SingleQueryPlanNode

com.mckoi.database.QueryPlan.SubsetNode

All Implemented Interfaces:

QueryPlanNode, Serializable, Cloneable

Enclosing class:

QueryPlan

public static class QueryPlan.SubsetNode
extends QueryPlan.SingleQueryPlanNode

The node for finding a subset and renaming the columns of the results in the child node.

See Also:

Serialized Form

Field Summary

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

child

Constructor Summary

Constructors

Constructor and Description
SubsetNode(QueryPlanNode child, Variable[] original_columns, Variable[] new_column_names)

Method Summary

Modifier and Type	Method and Description
Object	clone() Deep clone.
Table	evaluate(QueryContext context) Evaluates the node and returns the result as a Table.
Variable[]	getNewColumnNames() Returns the list of new column names that represent the new columns in this subset.
Variable[]	getOriginalColumns() Returns the list of original columns that represent the mappings from the columns in this subset.
void	setGivenName(TableName name) Sets the given table name of the resultant table.
String	titleString()

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

child, debugString, discoverCorrelatedVariables, discoverTableNames

Methods inherited from class java.lang.Object

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

Constructor Detail

SubsetNode

public SubsetNode(QueryPlanNode child,
                  Variable[] original_columns,
                  Variable[] new_column_names)

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

setGivenName

public void setGivenName(TableName name)

Sets the given table name of the resultant table. This is intended if we want to create a sub-query that has an aliased table name.

getOriginalColumns

public Variable[] getOriginalColumns()

Returns the list of original columns that represent the mappings from the columns in this subset.

getNewColumnNames

public Variable[] getNewColumnNames()

Returns the list of new column names that represent the new columns in this subset.

clone

public Object clone()
             throws CloneNotSupportedException

Description copied from class: QueryPlan.SingleQueryPlanNode

Deep clone.

Specified by:

clone in interface QueryPlanNode

Overrides:

clone in class QueryPlan.SingleQueryPlanNode

Throws:

CloneNotSupportedException

titleString

public String titleString()

Overrides:

titleString in class QueryPlan.SingleQueryPlanNode