org.h2.result

Class LazyResult

java.lang.Object

org.h2.result.FetchedResult

org.h2.result.LazyResult

All Implemented Interfaces:

java.lang.AutoCloseable, ResultInterface

public abstract class LazyResult
extends FetchedResult

Lazy execution support for queries.

Constructor Summary

Constructors

Constructor and Description
LazyResult(SessionLocal session, Expression[] expressions)

Method Summary

Modifier and Type	Method and Description
void	close() Close the result and delete any temporary files
protected abstract Value[]	fetchNextRow() Fetch next row or null if none available.
java.lang.String	getAlias(int i) Get the column alias name for the column.
java.lang.String	getColumnName(int i) Get the column name.
TypeInfo	getColumnType(int i) Get the column data type.
int	getFetchSize() Get the current fetch size for this result set.
int	getNullable(int i) Check if this column is nullable.
long	getRowCount() Get the number of rows in this object.
java.lang.String	getSchemaName(int i) Get the schema name for the column, if one exists.
java.lang.String	getTableName(int i) Get the table name for the column, if one exists.
boolean	hasNext() Check if this result has more rows to fetch.
boolean	isClosed() Check if this result set is closed.
boolean	isIdentity(int i) Check if this is an identity column.
boolean	isLazy() Check if this a lazy execution result.
void	reset() Go to the beginning of the result, that means before the first row.
void	setFetchSize(int fetchSize) Set the fetch size for this result set.
void	setLimit(long limit)
boolean	skip() Go to the next row and skip it.
protected boolean	skipNextRow() Skip next row.

Methods inherited from class org.h2.result.FetchedResult

createShallowCopy, currentRow, getRowId, isAfterLast, needToClose, next

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.h2.result.ResultInterface

getVisibleColumnCount

Constructor Detail

LazyResult

public LazyResult(SessionLocal session,
                  Expression[] expressions)

Method Detail

setLimit

public void setLimit(long limit)

isLazy

public boolean isLazy()

Description copied from interface: ResultInterface

Check if this a lazy execution result.

Returns:

true if it is a lazy result

reset

public void reset()

Description copied from interface: ResultInterface

Go to the beginning of the result, that means before the first row.

skip

public boolean skip()

Go to the next row and skip it.

Returns:

true if a row exists

hasNext

public boolean hasNext()

Description copied from interface: ResultInterface

Check if this result has more rows to fetch.

Returns:

true if it has

fetchNextRow

protected abstract Value[] fetchNextRow()

Fetch next row or null if none available.

Returns:

next row or null

skipNextRow

protected boolean skipNextRow()

Skip next row.

Returns:

true if next row was available

getRowCount

public long getRowCount()

Description copied from interface: ResultInterface

Get the number of rows in this object.

Returns:

the number of rows

isClosed

public boolean isClosed()

Description copied from interface: ResultInterface

Check if this result set is closed.

Returns:

true if it is

close

public void close()

Description copied from interface: ResultInterface

Close the result and delete any temporary files

getAlias

public java.lang.String getAlias(int i)

Description copied from interface: ResultInterface

Get the column alias name for the column.

Parameters:

i - the column number (starting with 0)

Returns:

the alias name

getSchemaName

public java.lang.String getSchemaName(int i)

Description copied from interface: ResultInterface

Get the schema name for the column, if one exists.

Parameters:

i - the column number (starting with 0)

Returns:

the schema name or null

getTableName

public java.lang.String getTableName(int i)

Description copied from interface: ResultInterface

Get the table name for the column, if one exists.

Parameters:

i - the column number (starting with 0)

Returns:

the table name or null

getColumnName

public java.lang.String getColumnName(int i)

Description copied from interface: ResultInterface

Get the column name.

Parameters:

i - the column number (starting with 0)

Returns:

the column name

getColumnType

public TypeInfo getColumnType(int i)

Description copied from interface: ResultInterface

Get the column data type.

Parameters:

i - the column number (starting with 0)

Returns:

the column data type

isIdentity

public boolean isIdentity(int i)

Description copied from interface: ResultInterface

Check if this is an identity column.

Parameters:

i - the column number (starting with 0)

Returns:

true for identity columns

getNullable

public int getNullable(int i)

Description copied from interface: ResultInterface

Check if this column is nullable.

Parameters:

i - the column number (starting with 0)

Returns:

Column.NULLABLE_*

setFetchSize

public void setFetchSize(int fetchSize)

Description copied from interface: ResultInterface

Set the fetch size for this result set.

Parameters:

fetchSize - the new fetch size

getFetchSize

public int getFetchSize()

Description copied from interface: ResultInterface

Get the current fetch size for this result set.

Returns:

the fetch size