org.apache.cassandra.cql3.selection

Class SimpleSelector.SimpleSelectorFactory

java.lang.Object

org.apache.cassandra.cql3.selection.Selector.Factory

org.apache.cassandra.cql3.selection.SimpleSelector.SimpleSelectorFactory

Enclosing class:

SimpleSelector

public static final class SimpleSelector.SimpleSelectorFactory
extends Selector.Factory

The Factory for SimpleSelector.

Method Summary

Modifier and Type	Method and Description
protected void	addColumnMapping(SelectionColumnMapping mapping, ColumnSpecification resultColumn) Record a mapping between the ColumnDefinitions that are used by the selector instances created by this factory and a column in the ResultSet.Metadata returned with a query.
void	addFetchedColumns(ColumnFilter.Builder builder) Adds the columns fetched by the selector created by this factory to the provided builder, assuming the factory is terminal (i.e.
boolean	areAllFetchedColumnsKnown() Checks if all the columns fetched by the selector created by this factory are known
ColumnMetadata	getColumn()
protected java.lang.String	getColumnName() Returns the name of the column corresponding to the output value of the selector instances created by this factory.
protected AbstractType<?>	getReturnType() Returns the type of the values returned by the selector instances created by this factory.
boolean	isSimpleSelectorFactory() Checks if this factory creates Selectors that simply return a column value.
boolean	isSimpleSelectorFactoryFor(int index) Checks if this factory creates Selectors that simply return the specified column.
Selector	newInstance(QueryOptions options) Creates a new Selector instance.

Methods inherited from class org.apache.cassandra.cql3.selection.Selector.Factory

addFunctionsTo, getColumnSpecification, isAggregateSelectorFactory, isTTLSelectorFactory, isWritetimeSelectorFactory

Methods inherited from class java.lang.Object

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

Method Detail

getColumnName

protected java.lang.String getColumnName()

Description copied from class: Selector.Factory

Returns the name of the column corresponding to the output value of the selector instances created by this factory.

Specified by:

getColumnName in class Selector.Factory

Returns:

a column name

getReturnType

protected AbstractType<?> getReturnType()

Description copied from class: Selector.Factory

Returns the type of the values returned by the selector instances created by this factory.

Specified by:

getReturnType in class Selector.Factory

Returns:

the selector output type

addColumnMapping

protected void addColumnMapping(SelectionColumnMapping mapping,
                                ColumnSpecification resultColumn)

Description copied from class: Selector.Factory

Record a mapping between the ColumnDefinitions that are used by the selector instances created by this factory and a column in the ResultSet.Metadata returned with a query. In most cases, this is likely to be a 1:1 mapping, but some selector instances may utilise multiple columns (or none at all) to produce a value (i.e. functions).

Specified by:

addColumnMapping in class Selector.Factory

Parameters:

mapping - the instance of the column mapping belonging to the current query's Selection

resultColumn - the column in the ResultSet.Metadata to which the ColumnDefinitions used by the Selector are to be mapped

newInstance

public Selector newInstance(QueryOptions options)

Description copied from class: Selector.Factory

Creates a new Selector instance.

Specified by:

newInstance in class Selector.Factory

Parameters:

options - the options of the query for which the instance is created (some selector depends on the bound values in particular).

Returns:

a new Selector instance

isSimpleSelectorFactory

public boolean isSimpleSelectorFactory()

Description copied from class: Selector.Factory

Checks if this factory creates Selectors that simply return a column value.

Overrides:

isSimpleSelectorFactory in class Selector.Factory

Returns:

true if this factory creates Selectors that simply return a column value, false otherwise.

isSimpleSelectorFactoryFor

public boolean isSimpleSelectorFactoryFor(int index)

Description copied from class: Selector.Factory

Checks if this factory creates Selectors that simply return the specified column.

Overrides:

isSimpleSelectorFactoryFor in class Selector.Factory

Parameters:

index - the column index

Returns:

true if this factory creates Selectors that simply return the specified column, false otherwise.

areAllFetchedColumnsKnown

public boolean areAllFetchedColumnsKnown()

Description copied from class: Selector.Factory

Checks if all the columns fetched by the selector created by this factory are known

Returns:

true if all the columns fetched by the selector created by this factory are known, false otherwise.

addFetchedColumns

public void addFetchedColumns(ColumnFilter.Builder builder)

Description copied from class: Selector.Factory

Adds the columns fetched by the selector created by this factory to the provided builder, assuming the factory is terminal (i.e. that isTerminal() == true).

Parameters:

builder - the column builder to add fetched columns (and potential subselection) to.

getColumn

public ColumnMetadata getColumn()