org.apache.derby.iapi.sql.dictionary

Class ForeignKeyConstraintDescriptor

java.lang.Object

org.apache.derby.iapi.sql.dictionary.TupleDescriptor

org.apache.derby.iapi.sql.dictionary.UniqueTupleDescriptor

org.apache.derby.iapi.sql.dictionary.ConstraintDescriptor

org.apache.derby.iapi.sql.dictionary.KeyConstraintDescriptor

org.apache.derby.iapi.sql.dictionary.ForeignKeyConstraintDescriptor

All Implemented Interfaces:

Dependable, Dependent, Provider

public class ForeignKeyConstraintDescriptor
extends KeyConstraintDescriptor

A foreign key.

Field Summary

Fields inherited from class org.apache.derby.iapi.sql.dictionary.ConstraintDescriptor

ALL, DISABLED, ENABLED, SYSCONSTRAINTS_STATE_FIELD

Fields inherited from interface org.apache.derby.catalog.Dependable

ACTIVATION, ALIAS, COLUMNS_IN_TABLE, COLUMNS_PERMISSION, CONGLOMERATE, CONSTRAINT, DEFAULT, FILE, HEAP, INDEX, PERM, PREPARED_STATEMENT, ROLE_GRANT, ROUTINE_PERMISSION, SCHEMA, SEQUENCE, STORED_PREPARED_STATEMENT, TABLE, TABLE_PERMISSION, TRIGGER, VIEW

Method Summary

Modifier and Type	Method and Description
int	getConstraintType() Gets an identifier telling what type of descriptor it is (UNIQUE, PRIMARY KEY, FOREIGN KEY, CHECK).
int	getRaDeleteRule() Gets a referential action rule on a DELETE
int	getRaUpdateRule() Gets a referential action rule on a UPDATE
ReferencedKeyConstraintDescriptor	getReferencedConstraint() Get the constraint that this FK references.
UUID	getReferencedConstraintId() Get the constraint id for the constraint that this FK references.
boolean	isSelfReferencingFK() Am I a self-referencing FK? True if my referenced constraint is on the same table as me.
boolean	needsToFire(int stmtType, int[] modifiedCols) Does this constraint need to fire on this type of DML? True if insert or update and columns intersect

Methods inherited from class org.apache.derby.iapi.sql.dictionary.KeyConstraintDescriptor

getConglomerateId, getIndexConglomerateDescriptor, getIndexId, getIndexUUIDString, hasBackingIndex, toString

Methods inherited from class org.apache.derby.iapi.sql.dictionary.ConstraintDescriptor

areColumnsComparable, columnIntersects, deferrable, drop, enforced, getClassType, getColumnDescriptors, getConstraintName, getConstraintText, getDependableFinder, getDescriptorName, getDescriptorType, getKeyColumns, getObjectID, getObjectName, getReferenceCount, getReferencedColumns, getSchemaDescriptor, getTableDescriptor, getTableId, getUUID, initiallyDeferred, isReferenced, isValid, makeInvalid, prepareToInvalidate, setDeferrable, setEnforced, setInitiallyDeferred

Methods inherited from class org.apache.derby.iapi.sql.dictionary.TupleDescriptor

isPersistent

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.derby.catalog.Dependable

isPersistent

Method Detail

getReferencedConstraint

public ReferencedKeyConstraintDescriptor getReferencedConstraint()
                                                          throws StandardException

Get the constraint that this FK references. Will return either a primary key or a unique key constraint.

Returns:

the constraint

Throws:

StandardException - on error

getReferencedConstraintId

public UUID getReferencedConstraintId()
                               throws StandardException

Get the constraint id for the constraint that this FK references. Will return either a primary key or a unique key constriant.

Returns:

the constraint id

Throws:

StandardException - on error

getConstraintType

public int getConstraintType()

Gets an identifier telling what type of descriptor it is (UNIQUE, PRIMARY KEY, FOREIGN KEY, CHECK).

Specified by:

getConstraintType in class ConstraintDescriptor

Returns:

An identifier telling what type of descriptor it is (UNIQUE, PRIMARY KEY, FOREIGN KEY, CHECK).

needsToFire

public boolean needsToFire(int stmtType,
                           int[] modifiedCols)

Does this constraint need to fire on this type of DML? True if insert or update and columns intersect

Specified by:

needsToFire in class ConstraintDescriptor

Parameters:

stmtType - the type of DML (StatementType.INSERT|StatementType.UPDATE|StatementType.DELETE)

modifiedCols - the columns modified, or null for all

Returns:

true/false

isSelfReferencingFK

public boolean isSelfReferencingFK()
                            throws StandardException

Am I a self-referencing FK? True if my referenced constraint is on the same table as me.

Returns:

true/false

Throws:

StandardException - on error

getRaDeleteRule

public int getRaDeleteRule()

Gets a referential action rule on a DELETE

Returns:

referential rule defined by the user during foreign key creattion for a delete (like CASCDE , RESTRICT ..etc)

getRaUpdateRule

public int getRaUpdateRule()

Gets a referential action rule on a UPDATE

Returns:

referential rule defined by the user during foreign key creattion for an UPDATE (like CASCDE , RESTRICT ..etc)