com.mckoi.database

Class QueryPlan.GroupNode

java.lang.Object

com.mckoi.database.QueryPlan.SingleQueryPlanNode

com.mckoi.database.QueryPlan.GroupNode

All Implemented Interfaces:

QueryPlanNode, Serializable, Cloneable

Enclosing class:

QueryPlan

public static class QueryPlan.GroupNode
extends QueryPlan.SingleQueryPlanNode

The node for performing a grouping operation on the columns of the child node. As well as grouping, any aggregate functions must also be defined with this plan.

NOTE: The whole child is a group if columns is null.

See Also:

Serialized Form

Field Summary

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

child

Constructor Summary

Constructors

Constructor and Description
GroupNode(QueryPlanNode child, Variable[] columns, Variable group_max_column, Expression[] function_list, String[] name_list) Groups over the given columns from the child.
GroupNode(QueryPlanNode child, Variable group_max_column, Expression[] function_list, String[] name_list) Groups over the entire child (always ends in 1 result in set).

Method Summary

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

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

child, debugString

Methods inherited from class java.lang.Object

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

Constructor Detail

GroupNode

public GroupNode(QueryPlanNode child,
                 Variable[] columns,
                 Variable group_max_column,
                 Expression[] function_list,
                 String[] name_list)

Groups over the given columns from the child.

GroupNode

public GroupNode(QueryPlanNode child,
                 Variable group_max_column,
                 Expression[] function_list,
                 String[] name_list)

Groups over the entire child (always ends in 1 result in set).

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 ArrayList discoverTableNames(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 ArrayList discoverCorrelatedVariables(int level,
                                             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 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