org.apache.derby.iapi.sql.dictionary

Class ReferencedKeyConstraintDescriptor

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.ReferencedKeyConstraintDescriptor

All Implemented Interfaces:

Dependable, Dependent, Provider

public class ReferencedKeyConstraintDescriptor
extends KeyConstraintDescriptor

A ReferencedConstraintDeescriptor is a primary key or a unique key that is referenced by 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	decrementReferenceCount() Decrement the reference count by one.
int	getConstraintType() Gets an identifier telling what type of descriptor it is (UNIQUE, PRIMARY KEY, FOREIGN KEY, CHECK).
ConstraintDescriptorList	getForeignKeyConstraints(int type) Get the referencing foreign key constraints
ConstraintDescriptorList	getNonSelfReferencingFK(int type) Am I referenced by a FK on another table? Return the list of those foreign constraints.
int	getReferenceCount() Get the number of enforced fks that reference this key.
boolean	hasSelfReferencingFK(ConstraintDescriptorList cdl, int type) Am I referenced by a FK on the same table?
int	incrementReferenceCount() Bump the reference count by one.
boolean	isReferenced() Is this constraint referenced? Returns true if there are enforced fks that reference this constraint.
boolean	needsToFire(int stmtType, int[] modifiedCols) Does this constraint need to fire on this type of DML? For referenced keys, fire if referenced by a fk, and stmt is delete or bulk insert replace, or stmt is 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, getReferencedColumns, getSchemaDescriptor, getTableDescriptor, getTableId, getUUID, initiallyDeferred, 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

getConstraintType

public final int getConstraintType()

Description copied from class: ConstraintDescriptor

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).

hasSelfReferencingFK

public boolean hasSelfReferencingFK(ConstraintDescriptorList cdl,
                                    int type)
                             throws StandardException

Am I referenced by a FK on the same table?

Parameters:

cdl - ConstraintDescriptorList for the table

type - ConstraintDescriptor.(ENABLED|DISABLED|ALL)

Returns:

true/false

Throws:

StandardException - on error

getNonSelfReferencingFK

public ConstraintDescriptorList getNonSelfReferencingFK(int type)
                                                 throws StandardException

Am I referenced by a FK on another table? Return the list of those foreign constraints.

Parameters:

type - ConstraintDescriptor.(ENABLED|DISABLED|ALL)

Returns:

list of constraints

Throws:

StandardException - on error

getForeignKeyConstraints

public ConstraintDescriptorList getForeignKeyConstraints(int type)
                                                  throws StandardException

Get the referencing foreign key constraints

Parameters:

type - ConstraintDescriptor.(ENABLED|DISABLED|ALL)

Returns:

the list of constraints (ConstraintDescriptorListImpl)

Throws:

StandardException - on error

isReferenced

public boolean isReferenced()

Is this constraint referenced? Returns true if there are enforced fks that reference this constraint.

Overrides:

isReferenced in class ConstraintDescriptor

Returns:

false

getReferenceCount

public int getReferenceCount()

Get the number of enforced fks that reference this key.

Overrides:

getReferenceCount in class ConstraintDescriptor

Returns:

the number of fks

incrementReferenceCount

public int incrementReferenceCount()

Bump the reference count by one.

Returns:

the number of fks

decrementReferenceCount

public int decrementReferenceCount()

Decrement the reference count by one.

Returns:

the number of fks

needsToFire

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

Does this constraint need to fire on this type of DML? For referenced keys, fire if referenced by a fk, and stmt is delete or bulk insert replace, or stmt is 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