org.h2.schema

Class Sequence

java.lang.Object

org.h2.engine.DbObjectBase

org.h2.schema.SchemaObjectBase

org.h2.schema.Sequence

All Implemented Interfaces:

DbObject, SchemaObject

public class Sequence
extends SchemaObjectBase

A sequence is created using the statement CREATE SEQUENCE

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_CACHE_SIZE The default cache size for sequences.

Fields inherited from class org.h2.engine.DbObjectBase

comment, database, trace

Fields inherited from interface org.h2.engine.DbObject

AGGREGATE, COMMENT, CONSTANT, CONSTRAINT, FUNCTION_ALIAS, INDEX, RIGHT, ROLE, SCHEMA, SEQUENCE, SETTING, SYNONYM, TABLE_OR_VIEW, TRIGGER, USER, USER_DATATYPE

Constructor Summary

Constructors

Constructor and Description
Sequence(Schema schema, int id, java.lang.String name, long startValue, long increment) Creates a new sequence for an auto-increment column.
Sequence(Schema schema, int id, java.lang.String name, java.lang.Long startValue, java.lang.Long increment, java.lang.Long cacheSize, java.lang.Long minValue, java.lang.Long maxValue, boolean cycle, boolean belongsToTable) Creates a new sequence.

Method Summary

Modifier and Type	Method and Description
void	checkRename() Check if this object can be renamed.
void	close() Flush the current value to disk and close this object.
void	flush(Session session) Flush the current value, including the margin, to disk.
void	flushWithoutMargin() Flush the current value to disk.
boolean	getBelongsToTable()
long	getCacheSize()
java.lang.String	getCreateSQL() Build a SQL statement to re-create this object.
java.lang.String	getCreateSQLForCopy(Table table, java.lang.String quotedName) Build a SQL statement to re-create the object, or to create a copy of the object with a different name or referencing a different table
long	getCurrentValue()
boolean	getCycle()
java.lang.String	getDropSQL() Build a SQL statement to drop this object.
long	getIncrement()
long	getMaxValue()
long	getMinValue()
long	getNext(Session session) Get the next value for this sequence.
int	getType() Get the object type.
void	modify(java.lang.Long startValue, java.lang.Long minValue, java.lang.Long maxValue, java.lang.Long increment) Allows the start value, increment, min value and max value to be updated atomically, including atomic validation.
void	removeChildrenAndResources(Session session) Remove all dependent objects and free all resources (files, blocks in files) of this object.
void	setBelongsToTable(boolean b)
void	setCacheSize(long cacheSize)
void	setCycle(boolean cycle)

Methods inherited from class org.h2.schema.SchemaObjectBase

getSchema, getSQL, initSchemaObjectBase, isHidden

Methods inherited from class org.h2.engine.DbObjectBase

getChildren, getComment, getDatabase, getId, getModificationId, getName, initDbObjectBase, invalidate, isTemporary, isValid, 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.engine.DbObject

getChildren, getComment, getDatabase, getId, getName, isTemporary, rename, setComment, setTemporary

Field Detail

DEFAULT_CACHE_SIZE

public static final int DEFAULT_CACHE_SIZE

The default cache size for sequences.

See Also:

Constant Field Values

Constructor Detail

Sequence

public Sequence(Schema schema,
                int id,
                java.lang.String name,
                long startValue,
                long increment)

Creates a new sequence for an auto-increment column.

Parameters:

schema - the schema

id - the object id

name - the sequence name

startValue - the first value to return

increment - the increment count

Sequence

public Sequence(Schema schema,
                int id,
                java.lang.String name,
                java.lang.Long startValue,
                java.lang.Long increment,
                java.lang.Long cacheSize,
                java.lang.Long minValue,
                java.lang.Long maxValue,
                boolean cycle,
                boolean belongsToTable)

Creates a new sequence.

Parameters:

schema - the schema

id - the object id

name - the sequence name

startValue - the first value to return

increment - the increment count

cacheSize - the number of entries to pre-fetch

minValue - the minimum value

maxValue - the maximum value

cycle - whether to jump back to the min value if needed

belongsToTable - whether this sequence belongs to a table (for auto-increment columns)

Method Detail

modify

public void modify(java.lang.Long startValue,
                   java.lang.Long minValue,
                   java.lang.Long maxValue,
                   java.lang.Long increment)

Allows the start value, increment, min value and max value to be updated atomically, including atomic validation. Useful because setting these attributes one after the other could otherwise result in an invalid sequence state (e.g. min value > max value, start value < min value, etc).

Parameters:

startValue - the new start value (null if no change)

minValue - the new min value (null if no change)

maxValue - the new max value (null if no change)

increment - the new increment (null if no change)

getBelongsToTable

public boolean getBelongsToTable()

getIncrement

public long getIncrement()

getMinValue

public long getMinValue()

getMaxValue

public long getMaxValue()

getCycle

public boolean getCycle()

setCycle

public void setCycle(boolean cycle)

getDropSQL

public java.lang.String getDropSQL()

Description copied from class: DbObjectBase

Build a SQL statement to drop this object.

Specified by:

getDropSQL in interface DbObject

Specified by:

getDropSQL in class DbObjectBase

Returns:

the SQL statement

getCreateSQLForCopy

public java.lang.String getCreateSQLForCopy(Table table,
                                            java.lang.String quotedName)

Description copied from interface: DbObject

Build a SQL statement to re-create the object, or to create a copy of the object with a different name or referencing a different table

Parameters:

table - the new table

quotedName - the quoted name

Returns:

the SQL statement

getCreateSQL

public java.lang.String getCreateSQL()

Description copied from class: DbObjectBase

Build a SQL statement to re-create this object.

Specified by:

getCreateSQL in interface DbObject

Specified by:

getCreateSQL in class DbObjectBase

Returns:

the SQL statement

getNext

public long getNext(Session session)

Get the next value for this sequence.

Parameters:

session - the session

Returns:

the next value

flushWithoutMargin

public void flushWithoutMargin()

Flush the current value to disk.

flush

public void flush(Session session)

Flush the current value, including the margin, to disk.

Parameters:

session - the session

close

public void close()

Flush the current value to disk and close this object.

getType

public int getType()

Description copied from interface: DbObject

Get the object type.

Returns:

the object type

removeChildrenAndResources

public void removeChildrenAndResources(Session session)

Description copied from class: DbObjectBase

Remove all dependent objects and free all resources (files, blocks in files) of this object.

Specified by:

removeChildrenAndResources in interface DbObject

Specified by:

removeChildrenAndResources in class DbObjectBase

Parameters:

session - the session

checkRename

public void checkRename()

Description copied from class: DbObjectBase

Check if this object can be renamed. System objects may not be renamed.

Specified by:

checkRename in interface DbObject

Specified by:

checkRename in class DbObjectBase

getCurrentValue

public long getCurrentValue()

setBelongsToTable

public void setBelongsToTable(boolean b)

setCacheSize

public void setCacheSize(long cacheSize)

getCacheSize

public long getCacheSize()