com.healthmarketscience.jackcess
Class Column

java.lang.Object
  com.healthmarketscience.jackcess.Column

All Implemented Interfaces:

Comparable<Column>

public class Column
extends Object
implements Comparable<Column>

Access database column definition

Author:

Tim McCune

Usage:

General: This class is general use.

Nested Class Summary

class	Column.AutoNumberGenerator Base class for the supported autonumber types.
static class	Column.SortOrder Information about the sort order (collation) for a textual column.

Field Summary

static Object	AUTO_NUMBER Meaningless placeholder object for inserting values in an autonumber column.
static byte	AUTO_NUMBER_FLAG_MASK mask for the auto number bit
static byte	AUTO_NUMBER_GUID_FLAG_MASK mask for the auto number guid bit
static byte	FIXED_LEN_FLAG_MASK mask for the fixed len bit
static Column.SortOrder	GENERAL_LEGACY_SORT_ORDER the "general" text sort order, legacy version (access 2000-2007)
static Column.SortOrder	GENERAL_SORT_ORDER the "general" text sort order, latest version (access 2010+)
static byte	HYPERLINK_FLAG_MASK mask for the hyperlink bit (on memo types)
static Object	KEEP_VALUE Meaningless placeholder object for updating rows which indicates that a given column should keep its existing value.
static byte	UNKNOWN_FLAG_MASK mask for the unknown bit (possible "can be null"?)

Constructor Summary

Column()

Column(JetFormat format)

Column(Table table, ByteBuffer buffer, int offset, int displayIndex)
Read a column definition in from a buffer

Method Summary

int	compareTo(Column other) Orders Columns by column number.
static short	countNonLongVariableLength(List<Column> columns)
static short	countVariableLength(List<Column> columns)
static String	decodeUncompressedText(byte[] textBytes, Charset charset)
static ByteBuffer	encodeUncompressedText(CharSequence text, Charset charset)
Column.AutoNumberGenerator	getAutoNumberGenerator() Returns the AutoNumberGenerator for this column if this is an autonumber column, null otherwise.
int	getColumnIndex()
short	getColumnNumber()
ComplexColumnInfo<? extends ComplexValue>	getComplexInfo() Returns extended functionality for "complex" columns.
Database	getDatabase()
int	getDisplayIndex()
int	getFixedDataOffset()
JetFormat	getFormat()
short	getLength()
short	getLengthInUnits()
String	getName()
PageChannel	getPageChannel()
byte	getPrecision()
PropertyMap	getProperties()
Object	getRowValue(Map<String,?> rowMap)
Object	getRowValue(Object[] rowArray)
byte	getScale()
int	getSQLType()
Table	getTable()
short	getTextCodePage()
Column.SortOrder	getTextSortOrder()
DataType	getType()
int	getVarLenTableIndex()
Column	getVersionHistoryColumn() Returns the column which tracks the version history for an "append only" column.
boolean	isAppendOnly() Whether or not this column is "append only" (its history is tracked by a separate version history column).
boolean	isAutoNumber()
boolean	isCompressedUnicode()
boolean	isHyperlink() Returns whether or not this is a hyperlink column (only possible for columns of type MEMO).
boolean	isVariableLength()
Object	read(byte[] data) Deserialize a raw byte value for this column into an Object
Object	read(byte[] data, ByteOrder order) Deserialize a raw byte value for this column into an Object
void	setAutoNumber(boolean autoNumber)
void	setColumnIndex(int newColumnIndex)
void	setColumnNumber(short newColumnNumber)
void	setCompressedUnicode(boolean newCompessedUnicode)
void	setFixedDataOffset(int newOffset)
void	setHyperlink(boolean hyperlink)
void	setLength(short length)
void	setLengthInUnits(short unitLength)
void	setName(String name)
void	setPrecision(byte newPrecision)
Object	setRowValue(Map<String,Object> rowMap, Object value)
Object	setRowValue(Object[] rowArray, Object value)
void	setScale(byte newScale)
void	setSQLType(int type)
void	setSQLType(int type, int lengthInUnits)
void	setTextSortOrder(Column.SortOrder newTextSortOrder)
void	setType(DataType type) Also sets the length and the variable length flag, inferred from the type.
void	setVariableLength(boolean variableLength)
void	setVarLenTableIndex(int idx)
void	setVersionHistoryColumn(Column versionHistoryCol)
static boolean	toBooleanValue(Object obj) Interpret a boolean value (null == false)
static byte[]	toByteArray(Object value)
static CharSequence	toCharSequence(Object value)
String	toString()
void	validate(JetFormat format) Checks that this column definition is valid.
ByteBuffer	write(Object obj, int remainingRowLength) Serialize an Object into a raw byte value for this column in little endian order
ByteBuffer	write(Object obj, int remainingRowLength, ByteOrder order) Serialize an Object into a raw byte value for this column
ByteBuffer	writeFixedLengthField(Object obj, ByteOrder order) Serialize an Object into a raw byte value for this column
ByteBuffer	writeLongValue(byte[] value, int remainingRowLength) Write an LVAL column into a ByteBuffer inline if it fits, otherwise in other data page(s).

Methods inherited from class java.lang.Object

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

Field Detail

AUTO_NUMBER

public static final Object AUTO_NUMBER

Meaningless placeholder object for inserting values in an autonumber column. it is not required that this value be used (any passed in value is ignored), but using this placeholder may make code more obvious.

Usage:

General: This field is general use.

KEEP_VALUE

public static final Object KEEP_VALUE

Meaningless placeholder object for updating rows which indicates that a given column should keep its existing value.

Usage:

General: This field is general use.

FIXED_LEN_FLAG_MASK

public static final byte FIXED_LEN_FLAG_MASK

mask for the fixed len bit

See Also:

Constant Field Values

Usage:

Advanced: This field is for advanced/internal use.

AUTO_NUMBER_FLAG_MASK

public static final byte AUTO_NUMBER_FLAG_MASK

mask for the auto number bit

See Also:

Constant Field Values

Usage:

Advanced: This field is for advanced/internal use.

AUTO_NUMBER_GUID_FLAG_MASK

public static final byte AUTO_NUMBER_GUID_FLAG_MASK

mask for the auto number guid bit

See Also:

Constant Field Values

Usage:

Advanced: This field is for advanced/internal use.

HYPERLINK_FLAG_MASK

public static final byte HYPERLINK_FLAG_MASK

mask for the hyperlink bit (on memo types)

See Also:

Constant Field Values

Usage:

Advanced: This field is for advanced/internal use.

UNKNOWN_FLAG_MASK

public static final byte UNKNOWN_FLAG_MASK

mask for the unknown bit (possible "can be null"?)

See Also:

Constant Field Values

Usage:

Advanced: This field is for advanced/internal use.

GENERAL_LEGACY_SORT_ORDER

public static final Column.SortOrder GENERAL_LEGACY_SORT_ORDER

the "general" text sort order, legacy version (access 2000-2007)

Usage:

Intermediate: This field requires moderate API knowledge.

GENERAL_SORT_ORDER

public static final Column.SortOrder GENERAL_SORT_ORDER

the "general" text sort order, latest version (access 2010+)

Usage:

Intermediate: This field requires moderate API knowledge.

Constructor Detail

Column

public Column()

Usage:

General: This method is general use.

Column

public Column(JetFormat format)

Usage:

Advanced: This method is for advanced/internal use.

Column

public Column(Table table,
              ByteBuffer buffer,
              int offset,
              int displayIndex)
       throws IOException

Read a column definition in from a buffer

Parameters:

table - owning table

buffer - Buffer containing column definition

offset - Offset in the buffer at which the column definition starts

Throws:

IOException

Usage:

Advanced: This method is for advanced/internal use.

Method Detail

getTable

public Table getTable()

Usage:

General: This method is general use.

getDatabase

public Database getDatabase()

Usage:

General: This method is general use.

getFormat

public JetFormat getFormat()

Usage:

Advanced: This method is for advanced/internal use.

getPageChannel

public PageChannel getPageChannel()

Usage:

Advanced: This method is for advanced/internal use.

getName

public String getName()

Usage:

General: This method is general use.

setName

public void setName(String name)

Usage:

Advanced: This method is for advanced/internal use.

isVariableLength

public boolean isVariableLength()

Usage:

Advanced: This method is for advanced/internal use.

setVariableLength

public void setVariableLength(boolean variableLength)

Usage:

Advanced: This method is for advanced/internal use.

isAutoNumber

public boolean isAutoNumber()

Usage:

General: This method is general use.

setAutoNumber

public void setAutoNumber(boolean autoNumber)

Usage:

General: This method is general use.

getColumnNumber

public short getColumnNumber()

Usage:

Advanced: This method is for advanced/internal use.

setColumnNumber

public void setColumnNumber(short newColumnNumber)

Usage:

Advanced: This method is for advanced/internal use.

getColumnIndex

public int getColumnIndex()

Usage:

Advanced: This method is for advanced/internal use.

setColumnIndex

public void setColumnIndex(int newColumnIndex)

Usage:

Advanced: This method is for advanced/internal use.

getDisplayIndex

public int getDisplayIndex()

Usage:

Advanced: This method is for advanced/internal use.

setType

public void setType(DataType type)

Also sets the length and the variable length flag, inferred from the type. For types with scale/precision, sets the scale and precision to default values.

Usage:

General: This method is general use.

getType

public DataType getType()

Usage:

General: This method is general use.

getSQLType

public int getSQLType()
               throws SQLException

Throws:

SQLException

Usage:

General: This method is general use.

setSQLType

public void setSQLType(int type)
                throws SQLException

Throws:

SQLException

Usage:

General: This method is general use.

setSQLType

public void setSQLType(int type,
                       int lengthInUnits)
                throws SQLException

Throws:

SQLException

Usage:

General: This method is general use.

isCompressedUnicode

public boolean isCompressedUnicode()

Usage:

General: This method is general use.

setCompressedUnicode

public void setCompressedUnicode(boolean newCompessedUnicode)

Usage:

General: This method is general use.

getPrecision

public byte getPrecision()

Usage:

General: This method is general use.

setPrecision

public void setPrecision(byte newPrecision)

Usage:

General: This method is general use.

getScale

public byte getScale()

Usage:

General: This method is general use.

setScale

public void setScale(byte newScale)

Usage:

General: This method is general use.

getTextSortOrder

public Column.SortOrder getTextSortOrder()

Usage:

Intermediate: This method requires moderate API knowledge.

setTextSortOrder

public void setTextSortOrder(Column.SortOrder newTextSortOrder)

Usage:

Advanced: This method is for advanced/internal use.

getTextCodePage

public short getTextCodePage()

Usage:

Intermediate: This method requires moderate API knowledge.

setLength

public void setLength(short length)

Usage:

General: This method is general use.

getLength

public short getLength()

Usage:

General: This method is general use.

setLengthInUnits

public void setLengthInUnits(short unitLength)

Usage:

General: This method is general use.

getLengthInUnits

public short getLengthInUnits()

Usage:

General: This method is general use.

setVarLenTableIndex

public void setVarLenTableIndex(int idx)

Usage:

Advanced: This method is for advanced/internal use.

getVarLenTableIndex

public int getVarLenTableIndex()

Usage:

Advanced: This method is for advanced/internal use.

setFixedDataOffset

public void setFixedDataOffset(int newOffset)

Usage:

Advanced: This method is for advanced/internal use.

getFixedDataOffset

public int getFixedDataOffset()

Usage:

Advanced: This method is for advanced/internal use.

isAppendOnly

public boolean isAppendOnly()

Whether or not this column is "append only" (its history is tracked by a separate version history column).

Usage:

General: This method is general use.

getVersionHistoryColumn

public Column getVersionHistoryColumn()

Returns the column which tracks the version history for an "append only" column.

Usage:

Intermediate: This method requires moderate API knowledge.

setVersionHistoryColumn

public void setVersionHistoryColumn(Column versionHistoryCol)

Usage:

Advanced: This method is for advanced/internal use.

isHyperlink

public boolean isHyperlink()

Returns whether or not this is a hyperlink column (only possible for columns of type MEMO).

Usage:

General: This method is general use.

setHyperlink

public void setHyperlink(boolean hyperlink)

Usage:

General: This method is general use.

getComplexInfo

public ComplexColumnInfo<? extends ComplexValue> getComplexInfo()

Returns extended functionality for "complex" columns.

Usage:

General: This method is general use.

getAutoNumberGenerator

public Column.AutoNumberGenerator getAutoNumberGenerator()

Returns the AutoNumberGenerator for this column if this is an autonumber column, null otherwise.

Usage:

Advanced: This method is for advanced/internal use.

getProperties

public PropertyMap getProperties()
                          throws IOException

Returns:

the properties for this column

Throws:

IOException

Usage:

General: This method is general use.

validate

public void validate(JetFormat format)

Checks that this column definition is valid.

Throws:

IllegalArgumentException - if this column definition is invalid.

Usage:

Advanced: This method is for advanced/internal use.

setRowValue

public Object setRowValue(Object[] rowArray,
                          Object value)

setRowValue

public Object setRowValue(Map<String,Object> rowMap,
                          Object value)

getRowValue

public Object getRowValue(Object[] rowArray)

getRowValue

public Object getRowValue(Map<String,?> rowMap)

read

public Object read(byte[] data)
            throws IOException

Deserialize a raw byte value for this column into an Object

Parameters:

data - The raw byte value

Returns:

The deserialized Object

Throws:

IOException

Usage:

Advanced: This method is for advanced/internal use.

read

public Object read(byte[] data,
                   ByteOrder order)
            throws IOException

Deserialize a raw byte value for this column into an Object

Parameters:

data - The raw byte value

order - Byte order in which the raw value is stored

Returns:

The deserialized Object

Throws:

IOException

Usage:

Advanced: This method is for advanced/internal use.

writeLongValue

public ByteBuffer writeLongValue(byte[] value,
                                 int remainingRowLength)
                          throws IOException

Write an LVAL column into a ByteBuffer inline if it fits, otherwise in other data page(s).

Parameters:

value - Value of the LVAL column

Returns:

A buffer containing the LVAL definition and (possibly) the column value (unless written to other pages)

Throws:

IOException

Usage:

Advanced: This method is for advanced/internal use.

write

public ByteBuffer write(Object obj,
                        int remainingRowLength)
                 throws IOException

Serialize an Object into a raw byte value for this column in little endian order

Parameters:

obj - Object to serialize

Returns:

A buffer containing the bytes

Throws:

IOException

Usage:

Advanced: This method is for advanced/internal use.

write

public ByteBuffer write(Object obj,
                        int remainingRowLength,
                        ByteOrder order)
                 throws IOException

Serialize an Object into a raw byte value for this column

Parameters:

obj - Object to serialize

order - Order in which to serialize

Returns:

A buffer containing the bytes

Throws:

IOException

Usage:

Advanced: This method is for advanced/internal use.

writeFixedLengthField

public ByteBuffer writeFixedLengthField(Object obj,
                                        ByteOrder order)
                                 throws IOException

Serialize an Object into a raw byte value for this column

Parameters:

obj - Object to serialize

order - Order in which to serialize

Returns:

A buffer containing the bytes

Throws:

IOException

Usage:

Advanced: This method is for advanced/internal use.

toString

public String toString()

Overrides:

toString in class Object

decodeUncompressedText

public static String decodeUncompressedText(byte[] textBytes,
                                            Charset charset)

Parameters:

textBytes - bytes of text to decode

charset - relevant charset

Returns:

the decoded string

Usage:

Advanced: This method is for advanced/internal use.

encodeUncompressedText

public static ByteBuffer encodeUncompressedText(CharSequence text,
                                                Charset charset)

Parameters:

text - Text to encode

charset - database charset

Returns:

A buffer with the text encoded

Usage:

Advanced: This method is for advanced/internal use.

compareTo

public int compareTo(Column other)

Orders Columns by column number.

Specified by:

compareTo in interface Comparable<Column>

Usage:

General: This method is general use.

countVariableLength

public static short countVariableLength(List<Column> columns)

Parameters:

columns - A list of columns in a table definition

Returns:

The number of variable length columns found in the list

Usage:

Advanced: This method is for advanced/internal use.

countNonLongVariableLength

public static short countNonLongVariableLength(List<Column> columns)

Parameters:

columns - A list of columns in a table definition

Returns:

The number of variable length columns which are not long values found in the list

Usage:

Advanced: This method is for advanced/internal use.

toCharSequence

public static CharSequence toCharSequence(Object value)
                                   throws IOException

Returns:

an appropriate CharSequence representation of the given object.

Throws:

IOException

Usage:

Advanced: This method is for advanced/internal use.

toByteArray

public static byte[] toByteArray(Object value)
                          throws IOException

Returns:

an appropriate byte[] representation of the given object.

Throws:

IOException

Usage:

Advanced: This method is for advanced/internal use.

toBooleanValue

public static boolean toBooleanValue(Object obj)

Interpret a boolean value (null == false)

Usage:

Advanced: This method is for advanced/internal use.