org.h2.constraint

Class Constraint

java.lang.Object

org.h2.engine.DbObject

org.h2.schema.SchemaObject

org.h2.constraint.Constraint

All Implemented Interfaces:

java.lang.Comparable<Constraint>, HasSQL

Direct Known Subclasses:

ConstraintCheck, ConstraintDomain, ConstraintReferential, ConstraintUnique

public abstract class Constraint
extends SchemaObject
implements java.lang.Comparable<Constraint>

The base class for constraint checking.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Constraint.Type

Field Summary

Fields

Modifier and Type	Field and Description
protected Table	table The table for which this constraint is defined.

Fields inherited from class org.h2.engine.DbObject

AGGREGATE, comment, COMMENT, CONSTANT, CONSTRAINT, database, DOMAIN, FUNCTION_ALIAS, INDEX, RIGHT, ROLE, SCHEMA, SEQUENCE, SETTING, SYNONYM, TABLE_OR_VIEW, trace, TRIGGER, USER

Fields inherited from interface org.h2.util.HasSQL

ADD_PLAN_INFORMATION, DEFAULT_SQL_FLAGS, NO_CASTS, QUOTE_ONLY_WHEN_REQUIRED, REPLACE_LOBS_FOR_TRACE, TRACE_SQL_FLAGS

Method Summary

Modifier and Type	Method and Description
abstract void	checkExistingData(SessionLocal session) Check the existing data.
abstract void	checkRow(SessionLocal session, Table t, Row oldRow, Row newRow) Check if this row fulfils the constraint.
int	compareTo(Constraint other)
abstract Constraint.Type	getConstraintType() The constraint type name
abstract java.lang.String	getCreateSQLWithoutIndexes() Get the SQL statement to create this constraint.
Expression	getExpression() Returns the CHECK expression or null.
Index	getIndex() Get the index of this constraint in the source table, or null if no index is used.
abstract java.util.HashSet<Column>	getReferencedColumns(Table table) Get all referenced columns.
ConstraintUnique	getReferencedConstraint() Returns the referenced unique constraint, or null.
Table	getRefTable()
Table	getTable()
int	getType() Get the object type.
abstract boolean	isBefore() Check if this constraint needs to be checked before updating the data.
boolean	isEverything(ExpressionVisitor visitor) Visit all elements in the constraint.
boolean	isHidden() Check whether this is a hidden object that doesn't appear in the meta data and in the script, and is not dropped on DROP ALL OBJECTS.
abstract void	rebuild() This method is called after a related table has changed (the table was renamed, or columns have been renamed).
abstract void	setIndexOwner(Index index) This index is now the owner of the specified index.
abstract boolean	usesIndex(Index index) Check if this constraint needs the specified index.

Methods inherited from class org.h2.schema.SchemaObject

getSchema, getSQL, getSQL

Methods inherited from class org.h2.engine.DbObject

checkRename, getChildren, getComment, getCreateSQL, getCreateSQLForCopy, getCreateSQLForMeta, getDatabase, getDropSQL, getId, getModificationId, getName, invalidate, isTemporary, isValid, removeChildrenAndResources, rename, setComment, setModified, setObjectName, setTemporary, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.h2.util.HasSQL

getTraceSQL

Field Detail

table

protected Table table

The table for which this constraint is defined.

Method Detail

getConstraintType

public abstract Constraint.Type getConstraintType()

The constraint type name

Returns:

the name

checkRow

public abstract void checkRow(SessionLocal session,
                              Table t,
                              Row oldRow,
                              Row newRow)

Check if this row fulfils the constraint. This method throws an exception if not.

Parameters:

session - the session

t - the table

oldRow - the old row

newRow - the new row

usesIndex

public abstract boolean usesIndex(Index index)

Check if this constraint needs the specified index.

Parameters:

index - the index

Returns:

true if the index is used

setIndexOwner

public abstract void setIndexOwner(Index index)

This index is now the owner of the specified index.

Parameters:

index - the index

getReferencedColumns

public abstract java.util.HashSet<Column> getReferencedColumns(Table table)

Get all referenced columns.

Parameters:

table - the table

Returns:

the set of referenced columns

getExpression

public Expression getExpression()

Returns the CHECK expression or null.

Returns:

the CHECK expression or null.

getCreateSQLWithoutIndexes

public abstract java.lang.String getCreateSQLWithoutIndexes()

Get the SQL statement to create this constraint.

Returns:

the SQL statement

isBefore

public abstract boolean isBefore()

Check if this constraint needs to be checked before updating the data.

Returns:

true if it must be checked before updating

checkExistingData

public abstract void checkExistingData(SessionLocal session)

Check the existing data. This method is called if the constraint is added after data has been inserted into the table.

Parameters:

session - the session

rebuild

public abstract void rebuild()

This method is called after a related table has changed (the table was renamed, or columns have been renamed).

getIndex

public Index getIndex()

Get the index of this constraint in the source table, or null if no index is used.

Returns:

the index

getReferencedConstraint

public ConstraintUnique getReferencedConstraint()

Returns the referenced unique constraint, or null.

Returns:

the referenced unique constraint, or null

getType

public int getType()

Description copied from class: DbObject

Get the object type.

Specified by:

getType in class DbObject

Returns:

the object type

getTable

public Table getTable()

getRefTable

public Table getRefTable()

compareTo

public int compareTo(Constraint other)

Specified by:

compareTo in interface java.lang.Comparable<Constraint>

isHidden

public boolean isHidden()

Description copied from class: SchemaObject

Check whether this is a hidden object that doesn't appear in the meta data and in the script, and is not dropped on DROP ALL OBJECTS.

Overrides:

isHidden in class SchemaObject

Returns:

true if it is hidden

isEverything

public boolean isEverything(ExpressionVisitor visitor)

Visit all elements in the constraint.

Parameters:

visitor - the visitor

Returns:

true if every visited expression returned true, or if there are no expressions