com.triactive.jdo.store.mapping
Class ObjectReferenceDatastoreIdMapping

java.lang.Object
  com.triactive.jdo.store.mapping.Mapping
      com.triactive.jdo.store.mapping.ColumnMapping
          com.triactive.jdo.store.mapping.OIDMapping
              com.triactive.jdo.store.mapping.ObjectReferenceDatastoreIdMapping

public class ObjectReferenceDatastoreIdMapping

extends OIDMapping

A column mapping that maps a referrence to a first-class persistent object to a single column via its datastore ID value.

Although the mapping is ostensibly for the entire object, the result of getObject() and setObject() is to transfer only the value of its ID column to/from the PreparedStatement/ResultSet.

Author:

Mike Martin

Field Summary

Fields inherited from class com.triactive.jdo.store.mapping.ColumnMapping

col, typeInfo

Fields inherited from class com.triactive.jdo.store.mapping.Mapping

dba, fmd, type

Constructor Summary

ObjectReferenceDatastoreIdMapping(DatabaseAdapter dba, java.lang.Class type)
Constructs a new object reference mapping for a given Java type.

ObjectReferenceDatastoreIdMapping(DatabaseAdapter dba, FieldMetaData fmd)
Constructs a new object reference mapping for a given persistent field.

Method Summary

void	defineConstraints(BaseTable table, StoreManager.MgmtTransaction mtx) Causes the mapping object to define whatever constraints it needs on its backing storage, relative to the specified table.
void	defineStorage(Table table, StoreManager.MgmtTransaction mtx) Causes the mapping object to define whatever backing storage it needs, relative to the specified table. Depending on the type of mapping, this may mean adding columns to the table, constructing other related table objects, or both. Storage in this case means only tables, columns, and primary keys. Other candidate keys, foreign keys, and indexes are added by Mapping.defineConstraints(com.triactive.jdo.store.sql.BaseTable, com.triactive.jdo.store.StoreManager.MgmtTransaction). The StoreManager will never call this method more than once.. For this class, the mapping must be for a persistent field or an exception is thrown. A single column is defined in table whose type and options are set according to the field metadata. Once defined, ColumnMapping.mapTo(com.triactive.jdo.store.sql.Column) is called to link this mapping to the new column..
java.lang.Object	getObject(PersistenceManager pm, java.sql.ResultSet rs, int param)
SqlExpression	newSqlExpression(QueryStatement.QueryColumn qsc) Returns an SQL expression representing a reference to a column in a query statement.
SqlExpression	newSqlLiteral(QueryStatement qs, java.lang.Object value) Returns an SQL expression representing the literal value of a Java object.
void	setObject(PersistenceManager pm, java.sql.PreparedStatement ps, int param, java.lang.Object value)

Methods inherited from class com.triactive.jdo.store.mapping.OIDMapping

mapTo

Methods inherited from class com.triactive.jdo.store.mapping.ColumnMapping

accessAsFieldIn, chooseColumnType, equals, getBoolean, getByte, getChar, getColumn, getDouble, getFloat, getInt, getLong, getShort, getSqlInsertionValue, getSqlUpdateValue, getString, getTypeInfo, hashCode, setBoolean, setByte, setChar, setDouble, setFloat, setInt, setLong, setShort, setString

Methods inherited from class com.triactive.jdo.store.mapping.Mapping

getDefaultMappingsByType, getFieldMetaData, getType

Methods inherited from class java.lang.Object

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

Constructor Detail

ObjectReferenceDatastoreIdMapping

public ObjectReferenceDatastoreIdMapping(DatabaseAdapter dba,
                                         java.lang.Class type)

Constructs a new object reference mapping for a given Java type.

Parameters:

dba - the database adapter

type - the Java class that this mapping maps to the database

ObjectReferenceDatastoreIdMapping

public ObjectReferenceDatastoreIdMapping(DatabaseAdapter dba,
                                         FieldMetaData fmd)

Constructs a new object reference mapping for a given persistent field.

Parameters:

dba - the database adapter

fmd - the field metadata for the field that this mapping maps to the database

Method Detail

defineStorage

public void defineStorage(Table table,
                          StoreManager.MgmtTransaction mtx)

Description copied from class: ColumnMapping

Causes the mapping object to define whatever backing storage it needs, relative to the specified table. Depending on the type of mapping, this may mean adding columns to the table, constructing other related table objects, or both.

Storage in this case means only tables, columns, and primary keys. Other candidate keys, foreign keys, and indexes are added by Mapping.defineConstraints(com.triactive.jdo.store.sql.BaseTable, com.triactive.jdo.store.StoreManager.MgmtTransaction).

The StoreManager will never call this method more than once..

For this class, the mapping must be for a persistent field or an exception is thrown. A single column is defined in table whose type and options are set according to the field metadata. Once defined, ColumnMapping.mapTo(com.triactive.jdo.store.sql.Column) is called to link this mapping to the new column.

Overrides:

defineStorage in class ColumnMapping

defineConstraints

public void defineConstraints(BaseTable table,
                              StoreManager.MgmtTransaction mtx)

Causes the mapping object to define whatever constraints it needs on its backing storage, relative to the specified table.

If the type of this object reference is specifically a persistence- capable class then a foreign key is defined from the reference column to the class table's primary key.

Overrides:

defineConstraints in class ColumnMapping

Parameters:

table - the table relative to which constraints should be defined.

setObject

public void setObject(PersistenceManager pm,
                      java.sql.PreparedStatement ps,
                      int param,
                      java.lang.Object value)

Overrides:

setObject in class OIDMapping

getObject

public java.lang.Object getObject(PersistenceManager pm,
                                  java.sql.ResultSet rs,
                                  int param)

Overrides:

getObject in class OIDMapping

newSqlLiteral

public SqlExpression newSqlLiteral(QueryStatement qs,
                                   java.lang.Object value)

Description copied from class: Mapping

Returns an SQL expression representing the literal value of a Java object. The object must be of a type used with this mapping.

Specified by:

newSqlLiteral in class Mapping

Parameters:

qs - the surrounding query statement for the expression

value - the literal value

newSqlExpression

public SqlExpression newSqlExpression(QueryStatement.QueryColumn qsc)

Description copied from class: ColumnMapping

Returns an SQL expression representing a reference to a column in a query statement.

Specified by:

newSqlExpression in class ColumnMapping

Parameters:

qsc - the query column reference