org.h2.value
Class Value

java.lang.Object
  org.h2.value.Value

Direct Known Subclasses:

ValueArray, ValueBoolean, ValueByte, ValueBytes, ValueDate, ValueDecimal, ValueDouble, ValueFloat, ValueInt, ValueLob, ValueLobDb, ValueLong, ValueNull, ValueResultSet, ValueShort, ValueString, ValueTime, ValueTimestamp, ValueUuid

public abstract class Value
extends java.lang.Object

This is the base class for all value classes. It provides conversion and comparison methods.

Nested Class Summary

static interface	Value.ValueBlob A "character large object".
static interface	Value.ValueClob A "binary large object".

Field Summary

static int	ARRAY The value type for ARRAY values.
static int	BLOB The value type for BLOB values.
static int	BOOLEAN The value type for BOOLEAN values.
static int	BYTE The value type for BYTE values.
static int	BYTES The value type for BYTES values.
static int	CLOB The value type for CLOB values.
static int	DATE The value type for DATE values.
static int	DECIMAL The value type for DECIMAL values.
static int	DOUBLE The value type for DOUBLE values.
static int	FLOAT The value type for FLOAT values.
static int	INT The value type for INT values.
static int	JAVA_OBJECT The value type for JAVA_OBJECT values.
static int	LONG The value type for LONG values.
static int	NULL The value type for NULL.
static int	RESULT_SET The value type for RESULT_SET values.
static int	SHORT The value type for SHORT values.
static int	STRING The value type for STRING values.
static int	STRING_FIXED The value type for string values with a fixed size.
static int	STRING_IGNORECASE The value type for case insensitive STRING values.
static int	TIME The value type for INT values.
static int	TIMESTAMP The value type for TIMESTAMP values.
static int	TYPE_COUNT The number of value types.
static int	UNKNOWN The data type is unknown at this time.
static int	UUID The value type for UUID values.

Constructor Summary

Value()

Method Summary

Value	add(Value v) Add a value and return the result.
boolean	checkPrecision(long precision) Check if the precision is smaller or equal than the given precision.
static void	clearCache() Clear the value cache.
void	close() Close the underlying resource, if any.
protected abstract int	compareSecure(Value v, CompareMode mode) Compare the value with another value of the same type.
int	compareTo(Value v, CompareMode mode) Compare this value against another value using the specified compare mode.
int	compareTypeSave(Value v, CompareMode mode) Compare this value against another value given that the values are of the same data type.
Value	convertPrecision(long precision) Convert the precision to the requested value.
Value	convertScale(boolean onlyToSmallerScale, int targetScale) Convert the scale.
Value	convertTo(int targetType) Compare a value to the specified type.
Value	copyToTemp() Copy this value to a temporary file if necessary.
Value	divide(Value v) Divide by a value and return the result.
abstract boolean	equals(java.lang.Object other) Check if the two values have the same hash code.
java.math.BigDecimal	getBigDecimal()
java.lang.Boolean	getBoolean()
byte	getByte()
byte[]	getBytes()
byte[]	getBytesNoCopy()
java.sql.Date	getDate()
java.sql.Date	getDateNoCopy()
abstract int	getDisplaySize() Get the display size in characters.
double	getDouble()
float	getFloat()
static int	getHigherOrder(int t1, int t2) Get the higher value order type of two value types.
java.io.InputStream	getInputStream()
int	getInt()
long	getLong()
int	getMemory() Get the memory used by this object.
abstract java.lang.Object	getObject() Get the value as an object.
abstract long	getPrecision() Get the precision.
java.io.Reader	getReader()
int	getScale()
short	getShort()
int	getSignum()
byte[]	getSmall() Get the byte array.
abstract java.lang.String	getSQL() Get the SQL expression for this value.
abstract java.lang.String	getString() Get the value as a string.
int	getTableId() Get the table (only for LOB object).
java.sql.Time	getTime()
java.sql.Time	getTimeNoCopy()
java.sql.Timestamp	getTimestamp()
java.sql.Timestamp	getTimestampNoCopy()
java.lang.String	getTraceSQL() Get a medium size SQL expression for debugging or tracing.
abstract int	getType() Get the value type.
abstract int	hashCode()
boolean	isFileBased() Check if this value is stored in it's own file.
boolean	isLinked() Check if this value is linked to a specific table.
Value	link(DataHandler handler, int tableId) Link a large value to a given table.
Value	multiply(Value v) Multiply with a value and return the result.
Value	negate() Return -value if this value support arithmetic operations.
abstract void	set(java.sql.PreparedStatement prep, int parameterIndex) Set the value as a parameter in a prepared statement.
Value	subtract(Value v) Subtract a value and return the result.
protected DbException	throwUnsupportedExceptionForType(java.lang.String op) Throw the exception that the feature is not support for the given data type.
java.lang.String	toString()
void	unlink() Mark any underlying resource as 'not linked to any table'.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

UNKNOWN

public static final int UNKNOWN

The data type is unknown at this time.

See Also:

Constant Field Values

NULL

public static final int NULL

The value type for NULL.

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Constant Field Values

BOOLEAN

public static final int BOOLEAN

The value type for BOOLEAN values.

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Constant Field Values

BYTE

public static final int BYTE

The value type for BYTE values.

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Constant Field Values

SHORT

public static final int SHORT

The value type for SHORT values.

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Constant Field Values

INT

public static final int INT

The value type for INT values.

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Constant Field Values

LONG

public static final int LONG

The value type for LONG values.

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Constant Field Values

DECIMAL

public static final int DECIMAL

The value type for DECIMAL values.

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Constant Field Values

DOUBLE

public static final int DOUBLE

The value type for DOUBLE values.

See Also:

Constant Field Values

FLOAT

public static final int FLOAT

The value type for FLOAT values.

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Constant Field Values

TIME

public static final int TIME

The value type for INT values.

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Constant Field Values

DATE

public static final int DATE

The value type for DATE values.

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Constant Field Values

TIMESTAMP

public static final int TIMESTAMP

The value type for TIMESTAMP values.

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Constant Field Values

BYTES

public static final int BYTES

The value type for BYTES values.

See Also:

Constant Field Values

STRING

public static final int STRING

The value type for STRING values.

See Also:

Constant Field Values

STRING_IGNORECASE

public static final int STRING_IGNORECASE

The value type for case insensitive STRING values.

See Also:

Constant Field Values

BLOB

public static final int BLOB

The value type for BLOB values.

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Constant Field Values

CLOB

public static final int CLOB

The value type for CLOB values.

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Constant Field Values

ARRAY

public static final int ARRAY

The value type for ARRAY values.

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Constant Field Values

RESULT_SET

public static final int RESULT_SET

The value type for RESULT_SET values.

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Constant Field Values

JAVA_OBJECT

public static final int JAVA_OBJECT

The value type for JAVA_OBJECT values.

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Constant Field Values

UUID

public static final int UUID

The value type for UUID values.

See Also:

Constant Field Values

STRING_FIXED

public static final int STRING_FIXED

The value type for string values with a fixed size.

See Also:

Constant Field Values

TYPE_COUNT

public static final int TYPE_COUNT

The number of value types.

See Also:

Constant Field Values

Constructor Detail

Value

public Value()

Method Detail

getSQL

public abstract java.lang.String getSQL()

Get the SQL expression for this value.

Returns:

the SQL expression

getType

public abstract int getType()

Get the value type.

Returns:

the type

getPrecision

public abstract long getPrecision()

Get the precision.

Returns:

the precision

getDisplaySize

public abstract int getDisplaySize()

Get the display size in characters.

Returns:

the display size

getMemory

public int getMemory()

Get the memory used by this object.

Returns:

the memory used in bytes

getString

public abstract java.lang.String getString()

Get the value as a string.

Returns:

the string

getObject

public abstract java.lang.Object getObject()

Get the value as an object.

Returns:

the object

set

public abstract void set(java.sql.PreparedStatement prep,
                         int parameterIndex)
                  throws java.sql.SQLException

Set the value as a parameter in a prepared statement.

Parameters:

prep - the prepared statement

parameterIndex - the parameter index

Throws:

java.sql.SQLException

compareSecure

protected abstract int compareSecure(Value v,
                                     CompareMode mode)

Compare the value with another value of the same type.

Parameters:

v - the other value

mode - the compare mode

Returns:

0 if both values are equal, -1 if the other value is smaller, and 1 otherwise

hashCode

public abstract int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public abstract boolean equals(java.lang.Object other)

Check if the two values have the same hash code. No data conversion is made; this method returns false if the other object is not of the same class. For some values, compareTo may return 0 even if equals return false. Example: ValueDecimal 0.0 and 0.00.

Overrides:

equals in class java.lang.Object

Parameters:

other - the other value

Returns:

true if they are equal

getHigherOrder

public static int getHigherOrder(int t1,
                                 int t2)

Get the higher value order type of two value types. If values need to be converted to match the other operands value type, the value with the lower order is converted to the value with the higher order.

Parameters:

t1 - the first value type

t2 - the second value type

Returns:

the higher value type of the two

clearCache

public static void clearCache()

Clear the value cache. Used for testing.

getBoolean

public java.lang.Boolean getBoolean()

getDate

public java.sql.Date getDate()

getDateNoCopy

public java.sql.Date getDateNoCopy()

getTime

public java.sql.Time getTime()

getTimeNoCopy

public java.sql.Time getTimeNoCopy()

getTimestamp

public java.sql.Timestamp getTimestamp()

getTimestampNoCopy

public java.sql.Timestamp getTimestampNoCopy()

getBytes

public byte[] getBytes()

getBytesNoCopy

public byte[] getBytesNoCopy()

getByte

public byte getByte()

getShort

public short getShort()

getBigDecimal

public java.math.BigDecimal getBigDecimal()

getDouble

public double getDouble()

getFloat

public float getFloat()

getInt

public int getInt()

getLong

public long getLong()

getInputStream

public java.io.InputStream getInputStream()

getReader

public java.io.Reader getReader()

add

public Value add(Value v)

Add a value and return the result.

Parameters:

v - the value to add

Returns:

the result

getSignum

public int getSignum()

negate

public Value negate()

Return -value if this value support arithmetic operations.

Returns:

the negative

subtract

public Value subtract(Value v)

Subtract a value and return the result.

Parameters:

v - the value to subtract

Returns:

the result

divide

public Value divide(Value v)

Divide by a value and return the result.

Parameters:

v - the value to divide by

Returns:

the result

multiply

public Value multiply(Value v)

Multiply with a value and return the result.

Parameters:

v - the value to multiply with

Returns:

the result

convertTo

public Value convertTo(int targetType)

Compare a value to the specified type.

Parameters:

targetType - the type of the returned value

Returns:

the converted value

compareTypeSave

public final int compareTypeSave(Value v,
                                 CompareMode mode)

Compare this value against another value given that the values are of the same data type.

Parameters:

v - the other value

mode - the compare mode

Returns:

0 if both values are equal, -1 if the other value is smaller, and 1 otherwise

compareTo

public final int compareTo(Value v,
                           CompareMode mode)

Compare this value against another value using the specified compare mode.

Parameters:

v - the other value

mode - the compare mode

Returns:

0 if both values are equal, -1 if the other value is smaller, and 1 otherwise

getScale

public int getScale()

convertScale

public Value convertScale(boolean onlyToSmallerScale,
                          int targetScale)

Convert the scale.

Parameters:

onlyToSmallerScale - if the scale should not reduced

targetScale - the requested scale

Returns:

the value

Throws:

java.sql.SQLException

convertPrecision

public Value convertPrecision(long precision)

Convert the precision to the requested value.

Parameters:

precision - the new precision

Returns:

the new value

Throws:

java.sql.SQLException

link

public Value link(DataHandler handler,
                  int tableId)

Link a large value to a given table. For values that are kept fully in memory this method has no effect.

Parameters:

handler - the data handler

tableId - the table to link to

Returns:

the new value or itself

Throws:

java.sql.SQLException

isLinked

public boolean isLinked()

Check if this value is linked to a specific table. For values that are kept fully in memory, this method returns false.

Returns:

true if it is

unlink

public void unlink()

Mark any underlying resource as 'not linked to any table'. For values that are kept fully in memory this method has no effect.

Throws:

java.sql.SQLException

isFileBased

public boolean isFileBased()

Check if this value is stored in it's own file. For values that are kept fully in memory, this method returns false.

Returns:

true if it is

close

public void close()

Close the underlying resource, if any. For values that are kept fully in memory this method has no effect.

Throws:

java.sql.SQLException

checkPrecision

public boolean checkPrecision(long precision)

Check if the precision is smaller or equal than the given precision.

Parameters:

precision - the maximum precision

Returns:

true if the precision of this value is smaller or equal to the given precision

getTraceSQL

public java.lang.String getTraceSQL()

Get a medium size SQL expression for debugging or tracing. If the precision is too large, only a subset of the value is returned.

Returns:

the SQL expression

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

throwUnsupportedExceptionForType

protected DbException throwUnsupportedExceptionForType(java.lang.String op)

Throw the exception that the feature is not support for the given data type.

Returns:

never returns normally

Throws:

the - exception

getTableId

public int getTableId()

Get the table (only for LOB object).

Returns:

the table id

getSmall

public byte[] getSmall()

Get the byte array.

Returns:

the byte array

copyToTemp

public Value copyToTemp()

Copy this value to a temporary file if necessary.

Returns:

the new value