de.mguennewig.pobjects.metadata
Class RefType

java.lang.Object
  de.mguennewig.pobjects.metadata.AbstractType
      de.mguennewig.pobjects.metadata.ScalarType
          de.mguennewig.pobjects.metadata.RefType

All Implemented Interfaces:

ReferenceToClass, Type

public class RefType
extends ScalarType
implements ReferenceToClass

Reference to an object.

In SQL terms, this is a foreign key constraint on the id attribute of a table. In the application it is a pointer to an object.

A foreign key constraint will be added automatically to class declarations.

Author:

Michael Günnewig

See Also:

ClassDecl.createImplicitConstraints(), ForeignKeyConstraint

Field Summary

static int	ON_DELETE_CASCADE
static int	ON_DELETE_NO_ACTION
static int	ON_DELETE_RESTRICT
static int	ON_DELETE_SET_DEFAULT
static int	ON_DELETE_SET_NULL
static int	ON_UPDATE_NO_ACTION
static int	ON_UPDATE_RESTRICT
static int	ON_UPDATE_SET_DEFAULT
static int	ON_UPDATE_SET_NULL

Fields inherited from interface de.mguennewig.pobjects.metadata.Type

CLASS_NAME, TYPE_NAME

Constructor Summary

RefType(java.lang.String targetModule, java.lang.String targetName, ClassDecl targetClass)
Creates a new reference with default actions for ON DELETE and ON UPDATE.

RefType(java.lang.String targetModule, java.lang.String targetName, ClassDecl targetClass, int onDelete)
Creates a new reference with default action for ON UPDATE.

RefType(java.lang.String targetModule, java.lang.String targetName, ClassDecl targetClass, int onDelete, int onUpdate)
Creates a new reference.

Method Summary

void	addMap(MapItem item) Adds a mapping to this type.
void	checkConstraints(Record rec, Column column) Checks all constraints imposed on values of this type.
java.lang.String	formatNative(java.lang.Object value) Map value from its `native' string representation to its internal representation based on the type.
java.lang.Class<?>	getJavaClass() Returns the Java class instance that is being used for the values of this type.
int	getMaxFieldSize() Returns the maximum field size required to enter a value of this type.
int	getOnDelete()
int	getOnUpdate()
java.lang.Object	getResult(JdbcContainer db, java.sql.ResultSet rs, int column) Reads the value for this type from the result set.
int	getResultInc() Returns the number of columns read from the ResultSet.
ClassDecl	getTargetClass() Returns the class declaration of the referenced table.
java.lang.String	getTargetModule() Returns the name of the module to which the referenced table belongs.
java.lang.String	getTargetName() Returns the name of the class the pointer (or foreign key) refers to.
java.lang.String	name(int variant) Returns different names depending on variant for the code generator.
java.lang.Object	parseNative(java.lang.String value) Parse value according to the `native' string representation of this type.
void	setParam(JdbcContainer db, java.sql.PreparedStatement statm, int pos, java.lang.Object value) Sets the parameter(s) starting at startPos.
void	setTargetClass(ClassDecl cl) Sets the class declaration of the referenced table.

Methods inherited from class de.mguennewig.pobjects.metadata.ScalarType

checkSyntax, expand, getMap, isScalar, labelToValue, valueToLabel

Methods inherited from class de.mguennewig.pobjects.metadata.AbstractType

format, getDescription, getTypeClass, parse, setDescription, setTypeClass

Methods inherited from class java.lang.Object

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

Field Detail

ON_DELETE_NO_ACTION

public static final int ON_DELETE_NO_ACTION

See Also:

Constant Field Values

ON_DELETE_RESTRICT

public static final int ON_DELETE_RESTRICT

See Also:

Constant Field Values

ON_DELETE_CASCADE

public static final int ON_DELETE_CASCADE

See Also:

Constant Field Values

ON_DELETE_SET_NULL

public static final int ON_DELETE_SET_NULL

See Also:

Constant Field Values

ON_DELETE_SET_DEFAULT

public static final int ON_DELETE_SET_DEFAULT

See Also:

Constant Field Values

ON_UPDATE_NO_ACTION

public static final int ON_UPDATE_NO_ACTION

See Also:

Constant Field Values

ON_UPDATE_RESTRICT

public static final int ON_UPDATE_RESTRICT

See Also:

Constant Field Values

ON_UPDATE_SET_NULL

public static final int ON_UPDATE_SET_NULL

See Also:

Constant Field Values

ON_UPDATE_SET_DEFAULT

public static final int ON_UPDATE_SET_DEFAULT

See Also:

Constant Field Values

Constructor Detail

RefType

public RefType(java.lang.String targetModule,
               java.lang.String targetName,
               ClassDecl targetClass)

Creates a new reference with default actions for ON DELETE and ON UPDATE.

Parameters:

targetModule - The name of the module to which the referenced table belongs.

targetName - The name of the class the pointer (or foreign key) refers to.

targetClass - The class declaration of the referenced table. This must be given or null with a later call to setTargetClass(de.mguennewig.pobjects.metadata.ClassDecl) before any usage of this type.

See Also:

RefType(String,String,ClassDecl,int, int), setTargetClass(de.mguennewig.pobjects.metadata.ClassDecl)

RefType

public RefType(java.lang.String targetModule,
               java.lang.String targetName,
               ClassDecl targetClass,
               int onDelete)

Creates a new reference with default action for ON UPDATE.

Parameters:

targetModule - The name of the module to which the referenced table belongs.

targetName - The name of the class the pointer (or foreign key) refers to.

targetClass - The class declaration of the referenced table. This must be given or null with a later call to setTargetClass(de.mguennewig.pobjects.metadata.ClassDecl) before any usage of this type.

onDelete - Specifies what the DBMS should do if the referenced row is deleted.

See Also:

RefType(String,String,ClassDecl,int, int), setTargetClass(de.mguennewig.pobjects.metadata.ClassDecl)

RefType

public RefType(java.lang.String targetModule,
               java.lang.String targetName,
               ClassDecl targetClass,
               int onDelete,
               int onUpdate)

Creates a new reference.

Parameters:

targetModule - The name of the module to which the referenced table belongs.

targetName - The name of the class the pointer (or foreign key) refers to.

targetClass - The class declaration of the referenced table. This must be given or null with a later call to setTargetClass(de.mguennewig.pobjects.metadata.ClassDecl) before any usage of this type.

onDelete - Specifies what the DBMS should do if the referenced row is deleted. Defaults to ON_DELETE_NO_ACTION.

onUpdate - Specifies what the DBMS should do if the referenced row is updated. Defaults to ON_UPDATE_NO_ACTION.

See Also:

setTargetClass(de.mguennewig.pobjects.metadata.ClassDecl)

Method Detail

getOnDelete

public final int getOnDelete()

getOnUpdate

public final int getOnUpdate()

getTargetModule

public final java.lang.String getTargetModule()

Returns the name of the module to which the referenced table belongs.

Specified by:

getTargetModule in interface ReferenceToClass

See Also:

ReferenceToClass.getTargetName(), ReferenceToClass.getTargetClass()

getTargetName

public final java.lang.String getTargetName()

Returns the name of the class the pointer (or foreign key) refers to.

Specified by:

getTargetName in interface ReferenceToClass

getTargetClass

public final ClassDecl getTargetClass()

Returns the class declaration of the referenced table.

Specified by:

getTargetClass in interface ReferenceToClass

See Also:

ReferenceToClass.setTargetClass(ClassDecl), ReferenceToClass.getTargetName()

setTargetClass

public final void setTargetClass(ClassDecl cl)

Sets the class declaration of the referenced table.

A call to this method is only necessary if the class declaration has not been passed to the constructor to solve circle problems.

Specified by:

setTargetClass in interface ReferenceToClass

addMap

public void addMap(MapItem item)

Adds a mapping to this type.

Specified by:

addMap in interface Type

Overrides:

addMap in class ScalarType

Throws:

java.lang.UnsupportedOperationException - always as the values of this type can't be mapped.

See Also:

Type.getJavaClass()

checkConstraints

public void checkConstraints(Record rec,
                             Column column)

Checks all constraints imposed on values of this type.

This method does nothing in the current implementation.

Specified by:

checkConstraints in interface Type

Overrides:

checkConstraints in class ScalarType

Parameters:

rec - The record which contains column.

column - The column of rec which has this type.

getJavaClass

public java.lang.Class<?> getJavaClass()

Returns the Java class instance that is being used for the values of this type.

Specified by:

getJavaClass in interface Type

getMaxFieldSize

public int getMaxFieldSize()

Returns the maximum field size required to enter a value of this type.

This is the maximum number of characters required to enter a string representation of all valid values of this type. The typical size of an input field may be much smaller.

Specified by:

getMaxFieldSize in interface Type

Overrides:

getMaxFieldSize in class ScalarType

formatNative

public java.lang.String formatNative(java.lang.Object value)

Map value from its `native' string representation to its internal representation based on the type.

This mapping is a one-to-one mapping of string values to the type's value set, without any translation based on MapItems associated with the type.

For example, an integer type's implementation would accept a value like `1' and translate it to the string `&dblquote;1&dblquote;', independent of any label associated with the value `1'.

The value null is always mapped to the empty string.

Specified by:

formatNative in interface Type

Overrides:

formatNative in class AbstractType

See Also:

Type.getJavaClass()

parseNative

public java.lang.Object parseNative(java.lang.String value)

Parse value according to the `native' string representation of this type.

This representation is a one-to-one mapping of the type's value set to strings, without any translation based on MapItems associated with the type.

For example, an integer type's implementation would accept a value like `"1"' and translate it to an integer object, but would reject a label like `"Yes"' that may be associated with the value `1'.

This method only parses the null value and throws an error for all other values, because the value can be an Id or the value of the visual field or even a user defined value.

Specified by:

parseNative in interface Type

Throws:

java.lang.UnsupportedOperationException - when the parameter does not represent the null.

See Also:

Type.addMap(MapItem), Type.parse(String)

getResult

public java.lang.Object getResult(JdbcContainer db,
                                  java.sql.ResultSet rs,
                                  int column)

Reads the value for this type from the result set.

Specified by:

getResult in interface Type

Overrides:

getResult in class ScalarType

See Also:

Type.getResultInc()

getResultInc

public int getResultInc()

Returns the number of columns read from the ResultSet.

Specified by:

getResultInc in interface Type

Overrides:

getResultInc in class ScalarType

See Also:

Type.getResult(JdbcContainer,ResultSet,int)

setParam

public void setParam(JdbcContainer db,
                     java.sql.PreparedStatement statm,
                     int pos,
                     java.lang.Object value)
              throws java.sql.SQLException

Sets the parameter(s) starting at startPos.

This method is the counterpart to Type.getResult(JdbcContainer,ResultSet,int) and Type.getResultInc().

Specified by:

setParam in interface Type

Throws:

java.sql.SQLException - if any database error occurs.

name

public java.lang.String name(int variant)

Returns different names depending on variant for the code generator.

Specified by:

name in interface Type

Overrides:

name in class AbstractType