com.healthmarketscience.jackcess
Class Table

java.lang.Object
  com.healthmarketscience.jackcess.Table

All Implemented Interfaces:

Iterable<Map<String,Object>>

public class Table
extends Object
implements Iterable<Map<String,Object>>

A single database table

Is not thread-safe.

Author:

Tim McCune

Nested Class Summary

class

Table.RowState Maintains the state of reading a row of data.

Field Summary

static byte	TYPE_SYSTEM Table type code for system tables
static byte	TYPE_USER Table type code for user tables

Method Summary

static int	addDataPageRow(ByteBuffer dataPage, int rowSize, JetFormat format) Updates free space and row info for a new row of the given size in the given data page.
void	addRow(Object... row) Add a single row to this table and write it to disk
void	addRows(List<? extends Object[]> rows) Add multiple rows to this table, only writing to disk after all rows have been written, and every time a data page is filled.
Object[]	asRow(Map<String,Object> rowMap) Converts a map of columnName -> columnValue to an array of row values appropriate for a call to addRow(Object...).
static short	cleanRowStart(short rowStart)
static int	countAutoNumberColumns(Collection<Column> columns)
Table.RowState	createRowState()
void	deleteCurrentRow() Delete the current row (retrieved by a call to getNextRow()).
void	deleteRow(Table.RowState rowState, RowId rowId) Delete the row on which the given rowState is currently positioned.
String	display()
String	display(long limit)
boolean	doUseBigIndex()
static short	findRowEnd(ByteBuffer buffer, int rowNum, JetFormat format)
static short	findRowStart(ByteBuffer buffer, int rowNum, JetFormat format)
Column	getColumn(String name)
int	getColumnCount()
List<Column>	getColumns()
Database	getDatabase()
JetFormat	getFormat()
Index	getIndex(String name)
List<Index>	getIndexes()
int	getMaxColumnCount()
String	getName()
Map<String,Object>	getNextRow()
Map<String,Object>	getNextRow(Collection<String> columnNames)
PageChannel	getPageChannel()
Map<String,Object>	getRow(Table.RowState rowState, RowId rowId, Collection<String> columnNames) Reads some columns from the given row.
int	getRowCount()
static int	getRowEndOffset(int rowNum, JetFormat format)
static int	getRowSpaceUsage(int rowSize, JetFormat format)
static int	getRowStartOffset(int rowNum, JetFormat format)
Object	getRowValue(Table.RowState rowState, RowId rowId, Column column) Reads a single column from the given row.
static boolean	isDeletedRow(short rowStart)
static boolean	isOverflowRow(short rowStart)
Iterator<Map<String,Object>>	iterator() Calls reset on this table and returns an unmodifiable Iterator which will iterate through all the rows of this table.
Iterator<Map<String,Object>>	iterator(Collection<String> columnNames) Calls reset on this table and returns an unmodifiable Iterator which will iterate through all the rows of this table, returning only the given columns.
static ByteBuffer	positionAtRowData(Table.RowState rowState, RowId rowId) Sets the position and limit in a new buffer using the given rowState according to the given row number and row end, following overflow row pointers as necessary.
static ByteBuffer	positionAtRowHeader(Table.RowState rowState, RowId rowId) Sets a new buffer to the correct row header page using the given rowState according to the given rowId.
void	reset() After calling this method, getNextRow will return the first row in the table
String	toString()
static int	writeTableDefinition(List<Column> columns, PageChannel pageChannel, JetFormat format) Writes a new table defined by the given columns to the database.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

TYPE_SYSTEM

public static final byte TYPE_SYSTEM

Table type code for system tables

See Also:

Constant Field Values

TYPE_USER

public static final byte TYPE_USER

Table type code for user tables

See Also:

Constant Field Values

Method Detail

getName

public String getName()

Returns:

The name of the table

doUseBigIndex

public boolean doUseBigIndex()

getMaxColumnCount

public int getMaxColumnCount()

getColumnCount

public int getColumnCount()

getDatabase

public Database getDatabase()

getFormat

public JetFormat getFormat()

getPageChannel

public PageChannel getPageChannel()

createRowState

public Table.RowState createRowState()

getColumns

public List<Column> getColumns()

Returns:

All of the columns in this table (unmodifiable List)

getColumn

public Column getColumn(String name)

Returns:

the column with the given name

getIndexes

public List<Index> getIndexes()

Returns:

All of the Indexes on this table (unmodifiable List)

getIndex

public Index getIndex(String name)

Returns:

the index with the given name

reset

public void reset()

After calling this method, getNextRow will return the first row in the table

deleteCurrentRow

public void deleteCurrentRow()
                      throws IOException

Delete the current row (retrieved by a call to getNextRow()).

Throws:

IOException

deleteRow

public void deleteRow(Table.RowState rowState,
                      RowId rowId)
               throws IOException

Delete the row on which the given rowState is currently positioned.

Throws:

IOException

getNextRow

public Map<String,Object> getNextRow()
                              throws IOException

Returns:

The next row in this table (Column name -> Column value)

Throws:

IOException

getNextRow

public Map<String,Object> getNextRow(Collection<String> columnNames)
                              throws IOException

Parameters:

columnNames - Only column names in this collection will be returned

Returns:

The next row in this table (Column name -> Column value)

Throws:

IOException

getRowValue

public Object getRowValue(Table.RowState rowState,
                          RowId rowId,
                          Column column)
                   throws IOException

Reads a single column from the given row.

Throws:

IOException

getRow

public Map<String,Object> getRow(Table.RowState rowState,
                                 RowId rowId,
                                 Collection<String> columnNames)
                          throws IOException

Reads some columns from the given row.

Parameters:

columnNames - Only column names in this collection will be returned

Throws:

IOException

positionAtRowHeader

public static ByteBuffer positionAtRowHeader(Table.RowState rowState,
                                             RowId rowId)
                                      throws IOException

Sets a new buffer to the correct row header page using the given rowState according to the given rowId. Deleted state is determined, but overflow row pointers are not followed.

Returns:

a ByteBuffer of the relevant page, or null if row was invalid

Throws:

IOException

positionAtRowData

public static ByteBuffer positionAtRowData(Table.RowState rowState,
                                           RowId rowId)
                                    throws IOException

Sets the position and limit in a new buffer using the given rowState according to the given row number and row end, following overflow row pointers as necessary.

Returns:

a ByteBuffer narrowed to the actual row data, or null if row was invalid or deleted

Throws:

IOException

iterator

public Iterator<Map<String,Object>> iterator()

Calls reset on this table and returns an unmodifiable Iterator which will iterate through all the rows of this table. Use of the Iterator follows the same restrictions as a call to getNextRow.

Specified by:

iterator in interface Iterable<Map<String,Object>>

Throws:

IllegalStateException - if an IOException is thrown by one of the operations, the actual exception will be contained within

iterator

public Iterator<Map<String,Object>> iterator(Collection<String> columnNames)

Calls reset on this table and returns an unmodifiable Iterator which will iterate through all the rows of this table, returning only the given columns. Use of the Iterator follows the same restrictions as a call to getNextRow.

Throws:

IllegalStateException - if an IOException is thrown by one of the operations, the actual exception will be contained within

writeTableDefinition

public static int writeTableDefinition(List<Column> columns,
                                       PageChannel pageChannel,
                                       JetFormat format)
                                throws IOException

Writes a new table defined by the given columns to the database.

Returns:

the first page of the new table's definition

Throws:

IOException

asRow

public Object[] asRow(Map<String,Object> rowMap)

Converts a map of columnName -> columnValue to an array of row values appropriate for a call to addRow(Object...).

addRow

public void addRow(Object... row)
            throws IOException

Add a single row to this table and write it to disk

Note, if this table has an auto-number column, the value written will be put back into the given row array.

Parameters:

row - row values for a single row. the row will be modified if this table contains an auto-number column, otherwise it will not be modified.

Throws:

IOException

addRows

public void addRows(List<? extends Object[]> rows)
             throws IOException

Add multiple rows to this table, only writing to disk after all rows have been written, and every time a data page is filled. This is much more efficient than calling addRow multiple times.

Note, if this table has an auto-number column, the values written will be put back into the given row arrays.

Parameters:

rows - List of Object[] row values. the rows will be modified if this table contains an auto-number column, otherwise they will not be modified.

Throws:

IOException

getRowCount

public int getRowCount()

toString

public String toString()

Overrides:

toString in class Object

display

public String display()
               throws IOException

Returns:

A simple String representation of the entire table in tab-delimited format

Throws:

IOException

display

public String display(long limit)
               throws IOException

Parameters:

limit - Maximum number of rows to display

Returns:

A simple String representation of the entire table in tab-delimited format

Throws:

IOException

addDataPageRow

public static int addDataPageRow(ByteBuffer dataPage,
                                 int rowSize,
                                 JetFormat format)

Updates free space and row info for a new row of the given size in the given data page. Positions the page for writing the row data.

Returns:

the row number of the new row

isDeletedRow

public static boolean isDeletedRow(short rowStart)

isOverflowRow

public static boolean isOverflowRow(short rowStart)

cleanRowStart

public static short cleanRowStart(short rowStart)

findRowStart

public static short findRowStart(ByteBuffer buffer,
                                 int rowNum,
                                 JetFormat format)

getRowStartOffset

public static int getRowStartOffset(int rowNum,
                                    JetFormat format)

findRowEnd

public static short findRowEnd(ByteBuffer buffer,
                               int rowNum,
                               JetFormat format)

getRowEndOffset

public static int getRowEndOffset(int rowNum,
                                  JetFormat format)

getRowSpaceUsage

public static int getRowSpaceUsage(int rowSize,
                                   JetFormat format)

countAutoNumberColumns

public static int countAutoNumberColumns(Collection<Column> columns)

Returns:

the number of "AutoNumber" columns in the given collection of columns.