org.apache.metamodel

Class CompositeDataContext

java.lang.Object

org.apache.metamodel.AbstractDataContext

org.apache.metamodel.CompositeDataContext

All Implemented Interfaces:

DataContext

public class CompositeDataContext
extends AbstractDataContext

DataContext for composite datacontexts. Composite DataContexts wrap several other datacontexts and makes cross-datastore querying possible.

Constructor Summary

Constructors

Constructor and Description
CompositeDataContext(Collection<DataContext> delegates)
CompositeDataContext(DataContext... delegates)

Method Summary

Methods

Modifier and Type	Method and Description
DataSet	executeQuery(Query query) Executes a query against the DataContext.
String	getDefaultSchemaName() Gets the name of the default schema.
Schema	getSchemaByNameInternal(String name) Gets a specific schema from the non-abstract implementation.
String[]	getSchemaNamesInternal() Gets schema names from the non-abstract implementation.

Methods inherited from class org.apache.metamodel.AbstractDataContext

compileQuery, executeQuery, executeQuery, getColumnByQualifiedLabel, getDefaultSchema, getSchemaByName, getSchemaNames, getSchemas, getTableByQualifiedLabel, isQualifiedPathDelim, onSchemaCacheRefreshed, parseQuery, query, refreshSchemas

Methods inherited from class java.lang.Object

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

Constructor Detail

CompositeDataContext

public CompositeDataContext(DataContext... delegates)

CompositeDataContext

public CompositeDataContext(Collection<DataContext> delegates)

Method Detail

executeQuery

public DataSet executeQuery(Query query)
                     throws MetaModelException

Description copied from interface: DataContext

Executes a query against the DataContext.

Parameters:

query - the query object to execute

Returns:

the DataSet produced from executing the query

Throws:

MetaModelException - if the specified query does not make sense or cannot be executed because of restraints on the type of datastore.

getDefaultSchemaName

public String getDefaultSchemaName()
                            throws MetaModelException

Description copied from class: AbstractDataContext

Gets the name of the default schema.

Specified by:

getDefaultSchemaName in class AbstractDataContext

Returns:

the default schema name.

Throws:

MetaModelException

getSchemaByNameInternal

public Schema getSchemaByNameInternal(String name)
                               throws MetaModelException

Description copied from class: AbstractDataContext

Gets a specific schema from the non-abstract implementation. This schema object will be cached except if the AbstractDataContext.refreshSchemas() method is called.

Specified by:

getSchemaByNameInternal in class AbstractDataContext

Parameters:

name - the name of the schema to get

Returns:

a schema object representing the named schema, or null if no such schema exists.

Throws:

MetaModelException

getSchemaNamesInternal

public String[] getSchemaNamesInternal()
                                throws MetaModelException

Description copied from class: AbstractDataContext

Gets schema names from the non-abstract implementation. These schema names will be cached except if the AbstractDataContext.refreshSchemas() method is called.

Specified by:

getSchemaNamesInternal in class AbstractDataContext

Returns:

an array of schema names.

Throws:

MetaModelException