Package org.datanucleus.store.rdbms.mapping.java

Class DiscriminatorMapping

java.lang.Object

org.datanucleus.store.rdbms.mapping.java.JavaTypeMapping

org.datanucleus.store.rdbms.mapping.java.SingleFieldMapping

org.datanucleus.store.rdbms.mapping.java.DiscriminatorMapping

Direct Known Subclasses:

DiscriminatorMapping.DiscriminatorLongMapping, DiscriminatorMapping.DiscriminatorStringMapping

public class DiscriminatorMapping
extends SingleFieldMapping

Mapping for a discriminator column in a table used in inheritance. The discriminator column is, by default, a String type, typically VARCHAR. It can however be "long" based if the user specifies INTEGER, BIGINT, or NUMERIC as the jdbc-type. In the latter case we make the necessary conversions between value types in this mapping class. This class is for internal use only. It should not be used in user mappings nor extended.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	DiscriminatorMapping.DiscriminatorLongMapping	Discriminator using a Long delegate.
static class	DiscriminatorMapping.DiscriminatorStringMapping	Discriminator using a String delegate.

Field Summary

Fields inherited from class org.datanucleus.store.rdbms.mapping.java.SingleFieldMapping

EXTENSION_CHECK_CONSTRAINT_VALUES

Fields inherited from class org.datanucleus.store.rdbms.mapping.java.JavaTypeMapping

absFieldNumber, columnMappings, mmd, referenceMapping, roleForMember, storeMgr, table, type

Constructor Summary

Constructors

Constructor	Description
DiscriminatorMapping(Table table, JavaTypeMapping delegate, org.datanucleus.metadata.DiscriminatorMetaData dismd)	Constructor.

Method Summary

Modifier and Type	Method	Description
void	addColumnMapping(ColumnMapping colMapping)	Mutator to add a column mapping
static DiscriminatorMapping	createDiscriminatorMapping(Table table, org.datanucleus.metadata.DiscriminatorMetaData dismd)	Convenience method to create a discriminator mapping in the specified table, using the provided discriminator metadata.
ColumnMapping	getColumnMapping(int index)	Accessor for a datastore mapping
ColumnMapping[]	getColumnMappings()	Accessor for the datastore mappings for this java type.
Class	getJavaType()	Accessor for the type represented here, returning the class itself
int	getNumberOfColumnMappings()	Accessor for the number of columns.
Object	getObject(org.datanucleus.ExecutionContext ec, ResultSet resultSet, int[] exprIndex)	Accessor for the object in this column
void	setObject(org.datanucleus.ExecutionContext ec, PreparedStatement ps, int[] exprIndex, Object value)	Mutator for the object in this column

Methods inherited from class org.datanucleus.store.rdbms.mapping.java.SingleFieldMapping

getBoolean, getByte, getChar, getDefaultLength, getDouble, getFloat, getInt, getJavaTypeForColumnMapping, getLong, getShort, getString, getValidValues, initialize, prepareColumnMapping, setBoolean, setByte, setChar, setDouble, setFloat, setInt, setLong, setShort, setString

Methods inherited from class org.datanucleus.store.rdbms.mapping.java.JavaTypeMapping

equals, failureMessage, getAbsoluteFieldNumber, getColumnMetaDataForMember, getMemberMetaData, getObject, getReferenceMapping, getRoleForMember, getStoreManager, getTable, getType, getValueForColumnMapping, hashCode, hasSimpleDatastoreRepresentation, includeInFetchStatement, includeInInsertStatement, includeInUpdateStatement, initialize, isNullable, isSerialised, performSetPostProcessing, representableAsStringLiteralInStatement, requiresSetPostProcessing, setAbsFieldNumber, setMemberMetaData, setObject, setReferenceMapping, setRoleForMember, setTable

Methods inherited from class java.lang.Object

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

Constructor Detail

DiscriminatorMapping

public DiscriminatorMapping(Table table,
                            JavaTypeMapping delegate,
                            org.datanucleus.metadata.DiscriminatorMetaData dismd)

Constructor.

Parameters:

table - Datastore table

delegate - The JavaTypeMapping to delegate storage

dismd - Metadata for the discriminator

Method Detail

getJavaType

public Class getJavaType()

Accessor for the type represented here, returning the class itself

Specified by:

getJavaType in class JavaTypeMapping

Returns:

This class.

setObject

public void setObject(org.datanucleus.ExecutionContext ec,
                      PreparedStatement ps,
                      int[] exprIndex,
                      Object value)

Mutator for the object in this column

Overrides:

setObject in class SingleFieldMapping

Parameters:

ec - ExecutionContext

ps - The statement

exprIndex - The indexes

value - The value to set it to

getObject

public Object getObject(org.datanucleus.ExecutionContext ec,
                        ResultSet resultSet,
                        int[] exprIndex)

Accessor for the object in this column

Overrides:

getObject in class SingleFieldMapping

Parameters:

ec - ExecutionContext

resultSet - The ResultSet to get the value from

exprIndex - The indexes

Returns:

The object

getNumberOfColumnMappings

public int getNumberOfColumnMappings()

Accessor for the number of columns.

Overrides:

getNumberOfColumnMappings in class JavaTypeMapping

Returns:

Number of columns

getColumnMapping

public ColumnMapping getColumnMapping(int index)

Accessor for a datastore mapping

Overrides:

getColumnMapping in class JavaTypeMapping

Parameters:

index - Index of the mapping

Returns:

The datastore mapping.

getColumnMappings

public ColumnMapping[] getColumnMappings()

Accessor for the datastore mappings for this java type.

Overrides:

getColumnMappings in class JavaTypeMapping

Returns:

The datastore mapping(s)

addColumnMapping

public void addColumnMapping(ColumnMapping colMapping)

Mutator to add a column mapping

Overrides:

addColumnMapping in class JavaTypeMapping

Parameters:

colMapping - Column mapping

createDiscriminatorMapping

public static DiscriminatorMapping createDiscriminatorMapping(Table table,
                                                              org.datanucleus.metadata.DiscriminatorMetaData dismd)

Convenience method to create a discriminator mapping in the specified table, using the provided discriminator metadata.

Parameters:

table - The table

dismd - The discriminator metadata

Returns:

Discriminator mapping