com.triactive.jdo.store.mapping
Class ColumnMapping

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

Direct Known Subclasses:

BigDecimalMapping, BigIntegerMapping, BooleanMapping, ByteArrayMapping, ByteMapping, CharacterMapping, DoubleMapping, FloatMapping, IntegerMapping, LongMapping, OIDMapping, ShortMapping, SqlDateMapping, SqlTimestampMapping, StringMapping

public abstract class ColumnMapping

extends Mapping

A database mapping that maps a Java type to a single column.

A ColumnMapping can set Java objects directly into JDBC PreparedStatement parameters, and get Java objects directly from JDBC ResultSet columns.

Author:

Mike Martin

See Also:

DatabaseAdapter.newColumnMapping(Class)

Field Summary

protected Column	col The column we are mapped to, or null for a prototypical mapping.
protected TypeInfo	typeInfo The JDBC type info.

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

dba, fmd, type

Constructor Summary

ColumnMapping(DatabaseAdapter dba, java.lang.Class type)
Constructs a new column mapping for a given Java type.

ColumnMapping(DatabaseAdapter dba, FieldMetaData fmd)
Constructs a new column mapping for a given persistent field.

Method Summary

SqlExpression	accessAsFieldIn(FcoExpression objExpr) Returns an SQL expression representing the persistent field mapped by this mapping within a particular first-class object expression.
TypeInfo	chooseColumnType(Column col) Chooses an appropriate SQL type for a column based on the column's options.
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. Depending on the type of mapping, this may mean adding any or all of candidate keys, foreign keys, or indexes to the specified table and/or other tables. This method only applies to base tables. It will always be called after calling Mapping.defineStorage(com.triactive.jdo.store.sql.Table, com.triactive.jdo.store.StoreManager.MgmtTransaction) and is passed the same table argument. The StoreManager will never call this method more than once..
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..
boolean	equals(java.lang.Object obj) Tests this object for equality with another object.
boolean	getBoolean(PersistenceManager pm, java.sql.ResultSet rs, int column)
byte	getByte(PersistenceManager pm, java.sql.ResultSet rs, int column)
char	getChar(PersistenceManager pm, java.sql.ResultSet rs, int column)
Column	getColumn() Returns the column this object is mapped to, if any.
double	getDouble(PersistenceManager pm, java.sql.ResultSet rs, int column)
float	getFloat(PersistenceManager pm, java.sql.ResultSet rs, int column)
int	getInt(PersistenceManager pm, java.sql.ResultSet rs, int column)
long	getLong(PersistenceManager pm, java.sql.ResultSet rs, int column)
java.lang.Object	getObject(PersistenceManager pm, java.sql.ResultSet rs, int column)
short	getShort(PersistenceManager pm, java.sql.ResultSet rs, int column)
java.lang.String	getSqlInsertionValue() Returns the SQL text to be included in INSERT statements when inserting a value into this mapping's column.
java.lang.String	getSqlUpdateValue() Returns the SQL text to be included in UPDATE statements when updating a value in this mapping's column.
java.lang.String	getString(PersistenceManager pm, java.sql.ResultSet rs, int column)
TypeInfo	getTypeInfo() Returns the actual SQL type used by this mapping.
int	hashCode() Returns a hash code value for this object.
void	mapTo(Column col) Links this mapping to a specific column.
abstract SqlExpression	newSqlExpression(QueryStatement.QueryColumn qsc) Returns an SQL expression representing a reference to a column in a query statement.
void	setBoolean(PersistenceManager pm, java.sql.PreparedStatement ps, int param, boolean value)
void	setByte(PersistenceManager pm, java.sql.PreparedStatement ps, int param, byte value)
void	setChar(PersistenceManager pm, java.sql.PreparedStatement ps, int param, char value)
void	setDouble(PersistenceManager pm, java.sql.PreparedStatement ps, int param, double value)
void	setFloat(PersistenceManager pm, java.sql.PreparedStatement ps, int param, float value)
void	setInt(PersistenceManager pm, java.sql.PreparedStatement ps, int param, int value)
void	setLong(PersistenceManager pm, java.sql.PreparedStatement ps, int param, long value)
void	setObject(PersistenceManager pm, java.sql.PreparedStatement ps, int param, java.lang.Object value)
void	setShort(PersistenceManager pm, java.sql.PreparedStatement ps, int param, short value)
void	setString(PersistenceManager pm, java.sql.PreparedStatement ps, int param, java.lang.String value)

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

getDefaultMappingsByType, getFieldMetaData, getType, newSqlLiteral

Methods inherited from class java.lang.Object

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

Field Detail

typeInfo

protected TypeInfo typeInfo

The JDBC type info.

col

protected Column col

The column we are mapped to, or null for a prototypical mapping.

Constructor Detail

ColumnMapping

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

Constructs a new column mapping for a given Java type.

Parameters:

dba - the database adapter

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

ColumnMapping

public ColumnMapping(DatabaseAdapter dba,
                     FieldMetaData fmd)

Constructs a new column 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)

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, mapTo(com.triactive.jdo.store.sql.Column) is called to link this mapping to the new column.

Specified by:

defineStorage in class Mapping

Parameters:

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

mtx - the context in which the mapping is being initialized

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. Depending on the type of mapping, this may mean adding any or all of candidate keys, foreign keys, or indexes to the specified table and/or other tables.

This method only applies to base tables. It will always be called after calling Mapping.defineStorage(com.triactive.jdo.store.sql.Table, com.triactive.jdo.store.StoreManager.MgmtTransaction) and is passed the same table argument.

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

This method is a no-op for this class.

Specified by:

defineConstraints in class Mapping

Parameters:

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

mtx - the context in which the mapping is being initialized

mapTo

public void mapTo(Column col)

Links this mapping to a specific column. Linkage involves at least two steps:

1. Calling the column's Column.mapWith(com.triactive.jdo.store.mapping.ColumnMapping) method
2. Setting this mapping's typeInfo to match the column's

This method can be called at most once for a given mapping. Subclasses may do extra work as a consequence of mapping themselves to a column, but they should always call super.mapTo(col) first.

Throws:

java.lang.IllegalStateException - if this object is already mapped to a column

chooseColumnType

public TypeInfo chooseColumnType(Column col)

Chooses an appropriate SQL type for a column based on the column's options.

Parameters:

col - the column

Returns:

the type info for the chosen SQL type.

getTypeInfo

public final TypeInfo getTypeInfo()

Returns the actual SQL type used by this mapping. If mapped to a specific column it always returns the SQL type of that column.

Returns:

the type info for the actual SQL type used by this mapping.

getColumn

public final Column getColumn()

Returns the column this object is mapped to, if any.

Returns:

the column this object is mapped to, or null if it's not mapped to a specific column.

getSqlInsertionValue

public java.lang.String getSqlInsertionValue()

Returns the SQL text to be included in INSERT statements when inserting a value into this mapping's column. This is usually "?" to indicate a JDBC statement parameter.

getSqlUpdateValue

public java.lang.String getSqlUpdateValue()

Returns the SQL text to be included in UPDATE statements when updating a value in this mapping's column. This is usually "?" to indicate a JDBC statement parameter.

accessAsFieldIn

public SqlExpression accessAsFieldIn(FcoExpression objExpr)

Description copied from class: Mapping

Returns an SQL expression representing the persistent field mapped by this mapping within a particular first-class object expression. Throws an exception if this mapping does not map a specified persistent field.

Specified by:

accessAsFieldIn in class Mapping

Parameters:

objExpr - an expression representing a first-class object

newSqlExpression

public abstract SqlExpression newSqlExpression(QueryStatement.QueryColumn qsc)

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

Parameters:

qsc - the query column reference

setBoolean

public void setBoolean(PersistenceManager pm,
                       java.sql.PreparedStatement ps,
                       int param,
                       boolean value)

getBoolean

public boolean getBoolean(PersistenceManager pm,
                          java.sql.ResultSet rs,
                          int column)

setChar

public void setChar(PersistenceManager pm,
                    java.sql.PreparedStatement ps,
                    int param,
                    char value)

getChar

public char getChar(PersistenceManager pm,
                    java.sql.ResultSet rs,
                    int column)

setByte

public void setByte(PersistenceManager pm,
                    java.sql.PreparedStatement ps,
                    int param,
                    byte value)

getByte

public byte getByte(PersistenceManager pm,
                    java.sql.ResultSet rs,
                    int column)

setShort

public void setShort(PersistenceManager pm,
                     java.sql.PreparedStatement ps,
                     int param,
                     short value)

getShort

public short getShort(PersistenceManager pm,
                      java.sql.ResultSet rs,
                      int column)

setInt

public void setInt(PersistenceManager pm,
                   java.sql.PreparedStatement ps,
                   int param,
                   int value)

getInt

public int getInt(PersistenceManager pm,
                  java.sql.ResultSet rs,
                  int column)

setLong

public void setLong(PersistenceManager pm,
                    java.sql.PreparedStatement ps,
                    int param,
                    long value)

getLong

public long getLong(PersistenceManager pm,
                    java.sql.ResultSet rs,
                    int column)

setFloat

public void setFloat(PersistenceManager pm,
                     java.sql.PreparedStatement ps,
                     int param,
                     float value)

getFloat

public float getFloat(PersistenceManager pm,
                      java.sql.ResultSet rs,
                      int column)

setDouble

public void setDouble(PersistenceManager pm,
                      java.sql.PreparedStatement ps,
                      int param,
                      double value)

getDouble

public double getDouble(PersistenceManager pm,
                        java.sql.ResultSet rs,
                        int column)

setString

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

getString

public java.lang.String getString(PersistenceManager pm,
                                  java.sql.ResultSet rs,
                                  int column)

setObject

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

getObject

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

hashCode

public int hashCode()

Returns a hash code value for this object.

Overrides:

hashCode in class Mapping

equals

public boolean equals(java.lang.Object obj)

Tests this object for equality with another object. Two ColumnMapping objects are equal if super.equals() is true and their columns (if any) are equal.

Overrides:

equals in class Mapping

Parameters:

obj - the object to compare with

Returns:

true if the objects are equal, false otherwise.