org.datanucleus.metadata

Class QueryResultMetaData

java.lang.Object

org.datanucleus.metadata.MetaData

org.datanucleus.metadata.QueryResultMetaData

All Implemented Interfaces:

Serializable

public class QueryResultMetaData
extends MetaData

Representation of the mapping of (SQL) Query results into a desired output form. The results of a (SQL) query can be mapped into a mixture of

• instances of persistent classes - mapping from the result columns to the persistent fields
• scalar values - names of result columns that are returned as scalars (Integer, String etc)

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	QueryResultMetaData.PersistentTypeMapping Class to wrap the mapping for a persistent type.

Field Summary

Fields

Modifier and Type	Field and Description
protected String	name Name of the query result mapping.
protected List<QueryResultMetaData.PersistentTypeMapping>	persistentTypeMappings Collection of mappings of persistent types returned from the result set.
protected List<String>	scalarColumns Collection of column names in the result set that are returned as scalars.

Fields inherited from class org.datanucleus.metadata.MetaData

extensions, LOCALISER, METADATA_CREATED_STATE, METADATA_INITIALISED_STATE, METADATA_POPULATED_STATE, METADATA_USED_STATE, metaDataState, parent, VENDOR_NAME, VENDOR_NAME_OLD

Constructor Summary

Constructors

Constructor and Description
QueryResultMetaData(String name) Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
void	addMappingForPersistentTypeMapping(String className, String fieldName, String columnName) Method to add a mapping for the specified persistent class.
void	addPersistentTypeMapping(String className, Map fieldColumnMap, String discrimColumn) Method to add a persistent type as an output for the mapping.
void	addScalarColumn(String columnName) Method to register a column as being scalar.
String	getName() Accessor for the name of the result mapping.
QueryResultMetaData.PersistentTypeMapping[]	getPersistentTypeMappings() Accessor for the persistent type mapping information for this result set.
String[]	getScalarColumns() Accessor for the names of the result set columns that are returned as scalars.

Methods inherited from class org.datanucleus.metadata.MetaData

addExtension, addExtension, assertIfInitialised, getExtensions, getNoOfExtensions, getParent, getValueForExtension, getValuesForExtension, hasExtension, initialise, isInitialised, isPopulated, isUsed, newExtensionMetaData, removeExtension, setParent, toString, toString

Methods inherited from class java.lang.Object

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

Field Detail

name

protected final String name

Name of the query result mapping.

persistentTypeMappings

protected List<QueryResultMetaData.PersistentTypeMapping> persistentTypeMappings

Collection of mappings of persistent types returned from the result set.

scalarColumns

protected List<String> scalarColumns

Collection of column names in the result set that are returned as scalars.

Constructor Detail

QueryResultMetaData

public QueryResultMetaData(String name)

Constructor.

Parameters:

name - The Query name

Method Detail

getName

public String getName()

Accessor for the name of the result mapping.

Returns:

Name of the mapping

addPersistentTypeMapping

public void addPersistentTypeMapping(String className,
                            Map fieldColumnMap,
                            String discrimColumn)

Method to add a persistent type as an output for the mapping.

Parameters:

className - Name of the persistent type

fieldColumnMap - Map of column name, keyed by the field name in the persistent type

discrimColumn - Name of any discriminator column

addMappingForPersistentTypeMapping

public void addMappingForPersistentTypeMapping(String className,
                                      String fieldName,
                                      String columnName)

Method to add a mapping for the specified persistent class.

Parameters:

className - Name of the persistent class

fieldName - Field in the persistent class

columnName - Name of the column in the result set to map to this field

addScalarColumn

public void addScalarColumn(String columnName)

Method to register a column as being scalar.

Parameters:

columnName - Name of the column

getPersistentTypeMappings

public QueryResultMetaData.PersistentTypeMapping[] getPersistentTypeMappings()

Accessor for the persistent type mapping information for this result set.

Returns:

Array of persistent types and their mapping info

getScalarColumns

public String[] getScalarColumns()

Accessor for the names of the result set columns that are returned as scalars.

Returns:

Column names whose values are returned as scalars