com.mckoi.database

Class QueryPlan.SingleRowTableNode

java.lang.Object

com.mckoi.database.QueryPlan.SingleRowTableNode

All Implemented Interfaces:

QueryPlanNode, Serializable, Cloneable

Enclosing class:

QueryPlan

public static class QueryPlan.SingleRowTableNode
extends Object
implements QueryPlanNode

A node for creating a table with a single row. This table is useful for queries that have no underlying row. For example, a pure functional table expression.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
SingleRowTableNode()

Method Summary

Modifier and Type	Method and Description
Object	clone() Deep clones this query plan.
void	debugString(int level, StringBuffer buf) Writes a textural representation of the node to the StringBuffer at the given indent level.
ArrayList	discoverCorrelatedVariables(int level, ArrayList list) Discovers all the correlated variables in the plan (and plan children) that reference a particular layer.
ArrayList	discoverTableNames(ArrayList list) Discovers a list of TableName that represent the sources that this query requires to complete itself.
Table	evaluate(QueryContext context) Evaluates the node and returns the result as a Table.
String	titleString()

Methods inherited from class java.lang.Object

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

Constructor Detail

SingleRowTableNode

public SingleRowTableNode()

Method Detail

discoverTableNames

public ArrayList discoverTableNames(ArrayList list)

Description copied from interface: QueryPlanNode

Discovers a list of TableName that represent the sources that this query requires to complete itself. For example, if this is a query plan of two joined table, the fully resolved names of both tables are returned.

The resultant list will not contain the same table name more than once. The resultant list contains TableName objects.

NOTE, if a table is aliased, the unaliased name is returned.

Specified by:

discoverTableNames in interface QueryPlanNode

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

Specified by:

evaluate in interface QueryPlanNode

discoverCorrelatedVariables

public ArrayList discoverCorrelatedVariables(int level,
                                             ArrayList list)

Description copied from interface: QueryPlanNode

Discovers all the correlated variables in the plan (and plan children) that reference a particular layer. For example, if we wanted to find all the CorrelatedVariable objects that reference the current layer, we would typically call 'discoverCorrelatedVariables(0, new ArrayList())'

Specified by:

discoverCorrelatedVariables in interface QueryPlanNode

clone

public Object clone()
             throws CloneNotSupportedException

Description copied from interface: QueryPlanNode

Deep clones this query plan.

Specified by:

clone in interface QueryPlanNode

Overrides:

clone in class Object

Throws:

CloneNotSupportedException

titleString

public String titleString()

debugString

public void debugString(int level,
                        StringBuffer buf)

Description copied from interface: QueryPlanNode

Writes a textural representation of the node to the StringBuffer at the given indent level.

Specified by:

debugString in interface QueryPlanNode