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

java.lang.Object
  org.apache.derby.iapi.sql.dictionary.TupleDescriptor
      org.apache.derby.iapi.sql.dictionary.ConstraintDescriptor

All Implemented Interfaces:

Dependable, Dependent, Provider, UniqueTupleDescriptor

Direct Known Subclasses:

CheckConstraintDescriptor, KeyConstraintDescriptor

public abstract class ConstraintDescriptor
extends TupleDescriptor
implements UniqueTupleDescriptor, Provider, Dependent

This class is used to get information from a ConstraintDescriptor. A ConstraintDescriptor can represent a constraint on a table or on a column.

Version:

0.1

Field Summary

static int	ALL
private ColumnDescriptorList	colDL
(package private) UUID	constraintId
(package private) java.lang.String	constraintName
private boolean	deferrable
static int	DISABLED
static int	ENABLED
private boolean	initiallyDeferred
(package private) boolean	isEnabled
private int[]	referencedColumns
private SchemaDescriptor	schemaDesc
static int	SYSCONSTRAINTS_STATE_FIELD
(package private) TableDescriptor	table

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

Constructor Summary

ConstraintDescriptor(DataDictionary dataDictionary, TableDescriptor table, java.lang.String constraintName, boolean deferrable, boolean initiallyDeferred, int[] referencedColumns, UUID constraintId, SchemaDescriptor schemaDesc, boolean isEnabled)
Constructor for a ConstraintDescriptor

Method Summary

boolean	areColumnsComparable(ColumnDescriptorList otherColumns) Indicates whether the column descriptor list is type comparable with the constraints columns.
boolean	columnIntersects(int[] columnArray) Does a column intersect with our referenced columns
boolean	deferrable() Returns TRUE if the constraint is deferrable (we will probably not do deferrable constraints in the initial release, but I want this to be part of the interface).
(package private) static boolean	doColumnsIntersect(int[] otherColumns, int[] referencedColumns) Does a column in the input set intersect with our referenced columns?
ConglomerateDescriptor	drop(LanguageConnectionContext lcc, boolean clearDependencies) Drop the constraint.
java.lang.String	getClassType() Get the provider's type.
ColumnDescriptorList	getColumnDescriptors() Get the column descriptors for all the columns referenced by this constraint.
abstract UUID	getConglomerateId()
java.lang.String	getConstraintName() Gets the name of the constraint.
java.lang.String	getConstraintText() Get the text of the constraint.
abstract int	getConstraintType() Gets an identifier telling what type of descriptor it is (UNIQUE, PRIMARY KEY, FOREIGN KEY, CHECK).
DependableFinder	getDependableFinder() Get an object which can be written to disk and which, when read from disk, will find or reconstruct this in-memory Dependable.
java.lang.String	getDescriptorName()
java.lang.String	getDescriptorType() Each descriptor must identify itself with its type; i.e index, check constraint whatever.
int[]	getKeyColumns() RESOLVE: For now the ConstraintDescriptor code stores the array of key columns in the field 'otherColumns'.
UUID	getObjectID() Get the provider's UUID
java.lang.String	getObjectName() Return the name of this Provider.
int	getReferenceCount() Get the number of enabled fks that reference this key.
int[]	getReferencedColumns() Returns an array of column ids (i.e. ordinal positions) for the columns referenced in this table for a primary key, unique key, referential, or check constraint.
SchemaDescriptor	getSchemaDescriptor() Get the SchemaDescriptor for the schema that this constraint belongs to.
TableDescriptor	getTableDescriptor() Get the table descriptor upon which this constraint is declared.
UUID	getTableId() Gets the UUID of the table the constraint is on.
UUID	getUUID() Gets the UUID of the constraint.
abstract boolean	hasBackingIndex() Does this constraint have a backing index?
boolean	initiallyDeferred() Returns TRUE if the constraint is initially deferred (we will probably not do initially deferred constraints in the initial release, but I want this to be part of the interface).
boolean	isEnabled() Is this constraint active?
boolean	isReferenced() Is this constraint referenced?
boolean	isValid() Check that all of the dependent's dependencies are valid.
void	makeInvalid(int action, LanguageConnectionContext lcc) Mark the dependent as invalid (due to at least one of its dependencies being invalid).
abstract boolean	needsToFire(int stmtType, int[] modifiedCols) Does this constraint need to fire on this type of DML?
void	prepareToInvalidate(Provider p, int action, LanguageConnectionContext lcc) Prepare to mark the dependent as invalid (due to at least one of its dependencies being invalid).
void	setDisabled() Set the constraint to disabled.
void	setEnabled() Set the constraint to enabled.
java.lang.String	toString() Convert the ColumnDescriptor to a String.

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

getColumnDependableFinder, getDataDictionary, getDependableFinder, isPersistent, setDataDictionary

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

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

isPersistent

Field Detail

ENABLED

public static final int ENABLED

See Also:

Constant Field Values

DISABLED

public static final int DISABLED

See Also:

Constant Field Values

ALL

public static final int ALL

See Also:

Constant Field Values

SYSCONSTRAINTS_STATE_FIELD

public static final int SYSCONSTRAINTS_STATE_FIELD

See Also:

Constant Field Values

table

TableDescriptor table

constraintName

final java.lang.String constraintName

deferrable

private final boolean deferrable

initiallyDeferred

private final boolean initiallyDeferred

isEnabled

boolean isEnabled

referencedColumns

private final int[] referencedColumns

constraintId

final UUID constraintId

schemaDesc

private final SchemaDescriptor schemaDesc

colDL

private ColumnDescriptorList colDL

Constructor Detail

ConstraintDescriptor

ConstraintDescriptor(DataDictionary dataDictionary,
                     TableDescriptor table,
                     java.lang.String constraintName,
                     boolean deferrable,
                     boolean initiallyDeferred,
                     int[] referencedColumns,
                     UUID constraintId,
                     SchemaDescriptor schemaDesc,
                     boolean isEnabled)

Constructor for a ConstraintDescriptor

Parameters:

dataDictionary - The data dictionary that this descriptor lives in

table - The descriptor of the table the constraint is on

constraintName - The name of the constraint.

deferrable - If the constraint can be deferred.

initiallyDeferred - If the constraint starts life deferred.

referencedColumns - columns that the constraint references

constraintId - UUID of constraint

schemaDesc - SchemaDescriptor

Method Detail

getTableId

public UUID getTableId()

Gets the UUID of the table the constraint is on.

Returns:

The UUID of the table the constraint is on.

getUUID

public UUID getUUID()

Gets the UUID of the constraint.

Specified by:

getUUID in interface UniqueTupleDescriptor

Returns:

The UUID of the constraint.

getConstraintName

public java.lang.String getConstraintName()

Gets the name of the constraint.

Returns:

A String containing the name of the constraint.

getConstraintType

public abstract int getConstraintType()

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

Returns:

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

getConglomerateId

public abstract UUID getConglomerateId()

getConstraintText

public java.lang.String getConstraintText()

Get the text of the constraint. (Only non-null/meaningful for check constraints.)

Returns:

The constraint text.

deferrable

public boolean deferrable()

Returns TRUE if the constraint is deferrable (we will probably not do deferrable constraints in the initial release, but I want this to be part of the interface).

Returns:

TRUE if the constraint is deferrable, FALSE if not

initiallyDeferred

public boolean initiallyDeferred()

Returns TRUE if the constraint is initially deferred (we will probably not do initially deferred constraints in the initial release, but I want this to be part of the interface).

Returns:

TRUE if the constraint is initially deferred, FALSE if not

getReferencedColumns

public int[] getReferencedColumns()

Returns an array of column ids (i.e. ordinal positions) for the columns referenced in this table for a primary key, unique key, referential, or check constraint.

Returns:

An array of column ids for those constraints that can be on columns (primary, unique key, referential constraints, and check constraints). For check and unique constraints, it returns an array of columns ids that are referenced in the constraint. For primary key and referential constraints, it returns an array of column ids for the columns in this table (i.e. the primary key columns for a primary key constraint, and the foreign key columns for a foreign key constraint.

hasBackingIndex

public abstract boolean hasBackingIndex()

Does this constraint have a backing index?

Returns:

boolean Whether or not there is a backing index for this constraint.

getSchemaDescriptor

public SchemaDescriptor getSchemaDescriptor()

Get the SchemaDescriptor for the schema that this constraint belongs to.

Returns:

SchemaDescriptor The SchemaDescriptor for this constraint.

getKeyColumns

public int[] getKeyColumns()

RESOLVE: For now the ConstraintDescriptor code stores the array of key columns in the field 'otherColumns'. Jerry plans to re-organize things. For now to minimize his rototill I've implemented this function on the old structures. All new code should use getKeyColumns to get a constraint's key columns.

See Also:

getKeyColumns()

isEnabled

public boolean isEnabled()

Is this constraint active?

Returns:

true/false

setEnabled

public void setEnabled()

Set the constraint to enabled. Does not update the data dictionary

setDisabled

public void setDisabled()

Set the constraint to disabled. Does not update the data dictionary

isReferenced

public boolean isReferenced()

Is this constraint referenced? Return false. Overridden by ReferencedKeyConstraints.

Returns:

false

getReferenceCount

public int getReferenceCount()

Get the number of enabled fks that reference this key. Overriden by ReferencedKeyConstraints.

Returns:

the number of fks

needsToFire

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

Does this constraint need to fire on this type of DML?

Parameters:

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

modifiedCols - the columns modified, or null for all

Returns:

true/false

getTableDescriptor

public TableDescriptor getTableDescriptor()

Get the table descriptor upon which this constraint is declared.

Returns:

the table descriptor

getColumnDescriptors

public ColumnDescriptorList getColumnDescriptors()
                                          throws StandardException

Get the column descriptors for all the columns referenced by this constraint.

Returns:

the column descriptor list

Throws:

StandardException - on error

areColumnsComparable

public boolean areColumnsComparable(ColumnDescriptorList otherColumns)
                             throws StandardException

Indicates whether the column descriptor list is type comparable with the constraints columns. The types have to be identical AND in the same order to succeed.

Parameters:

otherColumns - the columns to compare

Returns:

true/false

Throws:

StandardException - on error

columnIntersects

public boolean columnIntersects(int[] columnArray)

Does a column intersect with our referenced columns

Parameters:

columnArray - columns to check Note-- this is not a static method.

doColumnsIntersect

static boolean doColumnsIntersect(int[] otherColumns,
                                  int[] referencedColumns)

Does a column in the input set intersect with our referenced columns?

Parameters:

otherColumns - the columns to compare. If null, asssumed to mean all columns

referencedColumns - the columns referenced by the caller

Returns:

true/false

toString

public java.lang.String toString()

Convert the ColumnDescriptor to a String.

Overrides:

toString in class java.lang.Object

Returns:

A String representation of this ColumnDescriptor

getDependableFinder

public DependableFinder getDependableFinder()

Description copied from interface: Dependable

Get an object which can be written to disk and which, when read from disk, will find or reconstruct this in-memory Dependable.

Specified by:

getDependableFinder in interface Dependable

Returns:

the stored form of this provider

See Also:

Dependable.getDependableFinder()

getObjectName

public java.lang.String getObjectName()

Return the name of this Provider. (Useful for errors.)

Specified by:

getObjectName in interface Dependable

Returns:

String The name of this provider.

getObjectID

public UUID getObjectID()

Get the provider's UUID

Specified by:

getObjectID in interface Dependable

Returns:

The provider's UUID

getClassType

public java.lang.String getClassType()

Get the provider's type.

Specified by:

getClassType in interface Dependable

Returns:

char The provider's type.

isValid

public boolean isValid()

Check that all of the dependent's dependencies are valid.

Specified by:

isValid in interface Dependent

Returns:

true if the dependent is currently valid

prepareToInvalidate

public void prepareToInvalidate(Provider p,
                                int action,
                                LanguageConnectionContext lcc)
                         throws StandardException

Prepare to mark the dependent as invalid (due to at least one of its dependencies being invalid).

Specified by:

prepareToInvalidate in interface Dependent

Parameters:

action - The action causing the invalidation

p - the provider

lcc - The LanguageConnectionContext

Throws:

StandardException - thrown if unable to make it invalid

makeInvalid

public void makeInvalid(int action,
                        LanguageConnectionContext lcc)
                 throws StandardException

Mark the dependent as invalid (due to at least one of its dependencies being invalid). Always an error for a constraint -- should never have gotten here.

Specified by:

makeInvalid in interface Dependent

Parameters:

action - The action causing the invalidation

lcc - The LanguageConnectionContext

Throws:

StandardException - thrown if called in sanity mode

drop

public ConglomerateDescriptor drop(LanguageConnectionContext lcc,
                                   boolean clearDependencies)
                            throws StandardException

Drop the constraint. Clears dependencies, drops the backing index and removes the constraint from the list on the table descriptor. Does NOT do an dm.invalidateFor()

Returns:

If the backing conglomerate for this constraint was a) dropped and b) shared by other constraints/indexes, then this method will return a ConglomerateDescriptor that describes what a new backing conglomerate must look like to stay "sharable" across the remaining constraints/indexes. It is then up to the caller to create a corresponding conglomerate. We don't create the conglomerate here because depending on who called us, it might not make sense to create it--ex. if we get here because of a DROP TABLE, the DropTable action doesn't need to create a new backing conglomerate since the table (and all of its constraints/indexes) are going to disappear anyway.

Throws:

StandardException

getDescriptorName

public java.lang.String getDescriptorName()

Overrides:

getDescriptorName in class TupleDescriptor

See Also:

TupleDescriptor.getDescriptorName()

getDescriptorType

public java.lang.String getDescriptorType()

Description copied from class: TupleDescriptor

Each descriptor must identify itself with its type; i.e index, check constraint whatever.

Overrides:

getDescriptorType in class TupleDescriptor