org.apache.derby.iapi.types

Class SQLSmallint

java.lang.Object

org.apache.derby.iapi.types.DataType

org.apache.derby.iapi.types.NumberDataType

org.apache.derby.iapi.types.SQLSmallint

All Implemented Interfaces:

java.io.Externalizable, java.io.Serializable, java.lang.Comparable, Formatable, Storable, TypedFormat, DataValueDescriptor, NumberDataValue, Orderable

public final class SQLSmallint
extends NumberDataType

SQLSmallint satisfies the DataValueDescriptor interfaces (i.e., OrderableDataType). It implements a smallint column, e.g. for storing a column value; it can be specified when constructed to not allow nulls. Nullability cannot be changed after construction, as it affects the storage size and mechanism.

Because OrderableDataType is a subtype of ValueColumn, SQLSmallint can play a role in either a ValueColumn/Row or a OrderableDataType/Row, interchangeably.

We assume the store has a flag for nullness of the value, and simply return a 0-length array for the stored form when the value is null.

PERFORMANCE: There are likely alot of performance improvements possible for this implementation -- it new's Short more than it probably wants to.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
private static int	BASE_MEMORY_USAGE
private boolean	isnull
(package private) static int	SMALLINT_LENGTH
private short	value

Fields inherited from class org.apache.derby.iapi.types.NumberDataType

MAXLONG_PLUS_ONE, MINLONG_MINUS_ONE, ONE, ZERO, ZERO_DECIMAL

Fields inherited from interface org.apache.derby.iapi.types.NumberDataValue

MAX_DECIMAL_PRECISION_SCALE, MIN_DECIMAL_DIVIDE_SCALE

Fields inherited from interface org.apache.derby.iapi.types.DataValueDescriptor

UNKNOWN_LOGICAL_LENGTH

Fields inherited from interface org.apache.derby.iapi.types.Orderable

ORDER_OP_EQUALS, ORDER_OP_GREATEROREQUALS, ORDER_OP_GREATERTHAN, ORDER_OP_LESSOREQUALS, ORDER_OP_LESSTHAN

Constructor Summary

Constructors

Modifier	Constructor and Description
	SQLSmallint() No-arg constructor, required by Formattable. // This constructor also gets used when we are // allocating space for a short.
	SQLSmallint(short val)
	SQLSmallint(java.lang.Short obj)
private	SQLSmallint(short val, boolean isnull)

Method Summary

Methods

Modifier and Type	Method and Description
DataValueDescriptor	cloneValue(boolean forceMaterialization) Clone this DataValueDescriptor.
BooleanDataValue	equals(DataValueDescriptor left, DataValueDescriptor right) The = operator as called from the language module, as opposed to the storage module.
int	estimateMemoryUsage() Estimate the memory usage in bytes of the data value and the overhead of the class.
boolean	getBoolean() Gets the value in the data value descriptor as a boolean.
byte	getByte() Gets the value in the data value descriptor as a byte.
double	getDouble() Gets the value in the data value descriptor as a double.
float	getFloat() Gets the value in the data value descriptor as a float.
int	getInt() Gets the value in the data value descriptor as a int.
int	getLength() Gets the length of the data value.
long	getLong() Gets the value in the data value descriptor as a long.
DataValueDescriptor	getNewNull() Get a new null value of the same type as this data value.
java.lang.Object	getObject() Gets the value in the data value descriptor as a int.
short	getShort() Gets the value in the data value descriptor as a short.
java.lang.String	getString() Gets the value in the data value descriptor as a String.
int	getTypeFormatId() Return my format identifier.
java.lang.String	getTypeName() Get the SQL name of the datatype
BooleanDataValue	greaterOrEquals(DataValueDescriptor left, DataValueDescriptor right) The >= operator as called from the language module, as opposed to the storage module.
BooleanDataValue	greaterThan(DataValueDescriptor left, DataValueDescriptor right) The > operator as called from the language module, as opposed to the storage module.
int	hashCode()
protected boolean	isNegative() This method implements the isNegative method.
boolean	isNull() always false for non-nullable columns
BooleanDataValue	lessOrEquals(DataValueDescriptor left, DataValueDescriptor right) The <= operator as called from the language module, as opposed to the storage module.
BooleanDataValue	lessThan(DataValueDescriptor left, DataValueDescriptor right) The < operator as called from the language module, as opposed to the storage module.
NumberDataValue	minus(NumberDataValue result) This method implements the unary minus operator for smallint.
NumberDataValue	mod(NumberDataValue dividend, NumberDataValue divisor, NumberDataValue result) mod(smallint, smallint)
BooleanDataValue	notEquals(DataValueDescriptor left, DataValueDescriptor right) The <> operator as called from the language module, as opposed to the storage module.
void	readExternal(java.io.ObjectInput in)
void	restoreToNull() Restore this object to its (SQL)null value.
protected void	setFrom(DataValueDescriptor theValue) Set the value of this DataValueDescriptor based on the value of the specified DataValueDescriptor.
void	setInto(java.sql.PreparedStatement ps, int position) Set the value into a PreparedStatement.
void	setInto(java.sql.ResultSet rs, int position) Set this value into a ResultSet for a subsequent ResultSet.insertRow or ResultSet.updateRow.
void	setValue(boolean theValue) Set the value.
void	setValue(byte theValue) Common code to handle converting a byte to this value by using the int to this value conversion.
void	setValue(double theValue) Set the value of this DataValueDescriptor to the given double value At DataType level just throws an error lower classes will override
void	setValue(float theValue) Set the value of this DataValueDescriptor to the given float value At DataType level just throws an error lower classes will override
void	setValue(int theValue) Set the value of this DataValueDescriptor to the given int value At DataType level just throws an error lower classes will override
void	setValue(long theValue) Set the value of this DataValueDescriptor to the given long value At DataType level just throws an error lower classes will override
void	setValue(short theValue) Common code to handle converting a short to this value by using the int to this value conversion.
void	setValue(java.lang.String theValue) Set the value of this DataValueDescriptor.
void	setValueFromResultSet(java.sql.ResultSet resultSet, int colNumber, boolean isNullable) Set the value based on the value for the specified DataValueDescriptor from the specified ResultSet.
NumberDataValue	times(NumberDataValue left, NumberDataValue right, NumberDataValue result) This method implements the * operator for "smallint * smallint".
java.lang.String	toString()
protected int	typeCompare(DataValueDescriptor arg) Compare this (not null) to a non-null value.
int	typePrecedence() Each built-in type in JSQL has a precedence.
void	writeExternal(java.io.ObjectOutput out)

Methods inherited from class org.apache.derby.iapi.types.NumberDataType

absolute, compare, compare, divide, divide, getDecimalValuePrecision, getDecimalValueScale, minus, normalizeDOUBLE, normalizeREAL, normalizeREAL, objectNull, plus, setBigDecimal, setObject, setValue, sqrt, typeToBigDecimal

Methods inherited from class org.apache.derby.iapi.types.DataType

checkHostVariable, cloneHolder, coalesce, compare, compare, compareTo, dataTypeConversion, equals, flip, genericSetObject, getBytes, getDate, getStream, getTime, getTimestamp, getTraceString, getTypeName, hasStream, in, invalidFormat, isNotNull, isNullOp, normalize, outOfRange, readExternalFromArray, recycle, setObjectForCast, setToNull, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, throwLangSetMismatch, throwLangSetMismatch

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.derby.iapi.types.DataValueDescriptor

checkHostVariable, cloneHolder, coalesce, compare, compare, getBytes, getDate, getStream, getTime, getTimestamp, getTraceString, hasStream, in, isNotNull, isNullOp, normalize, readExternalFromArray, recycle, setObjectForCast, setToNull, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue

Field Detail

SMALLINT_LENGTH

static final int SMALLINT_LENGTH

See Also:

Constant Field Values

BASE_MEMORY_USAGE

private static final int BASE_MEMORY_USAGE

value

private short value

isnull

private boolean isnull

Constructor Detail

SQLSmallint

public SQLSmallint()

No-arg constructor, required by Formattable. // This constructor also gets used when we are // allocating space for a short.

SQLSmallint

public SQLSmallint(short val)

SQLSmallint

private SQLSmallint(short val,
           boolean isnull)

SQLSmallint

public SQLSmallint(java.lang.Short obj)

Method Detail

getInt

public int getInt()

Description copied from class: DataType

Gets the value in the data value descriptor as a int. Throws an exception if the data value is not receivable as a int.

Specified by:

getInt in interface DataValueDescriptor

Overrides:

getInt in class DataType

Returns:

The data value as a int.

See Also:

DataValueDescriptor.getInt()

getByte

public byte getByte()
             throws StandardException

Description copied from class: DataType

Gets the value in the data value descriptor as a byte. Throws an exception if the data value is not receivable as a byte.

Specified by:

getByte in interface DataValueDescriptor

Overrides:

getByte in class DataType

Returns:

The data value as a byte.

Throws:

StandardException - thrown on failure to convert

See Also:

DataValueDescriptor.getByte()

getShort

public short getShort()

Description copied from class: DataType

Gets the value in the data value descriptor as a short. Throws an exception if the data value is not receivable as a short.

Specified by:

getShort in interface DataValueDescriptor

Overrides:

getShort in class DataType

Returns:

The data value as a short.

See Also:

DataValueDescriptor.getShort()

getLong

public long getLong()

Description copied from class: DataType

Gets the value in the data value descriptor as a long. Throws an exception if the data value is not receivable as a long.

Specified by:

getLong in interface DataValueDescriptor

Overrides:

getLong in class DataType

Returns:

The data value as a long.

See Also:

DataValueDescriptor.getLong()

getFloat

public float getFloat()

Description copied from class: DataType

Gets the value in the data value descriptor as a float. Throws an exception if the data value is not receivable as a float.

Specified by:

getFloat in interface DataValueDescriptor

Overrides:

getFloat in class DataType

Returns:

The data value as a float.

See Also:

DataValueDescriptor.getFloat()

getDouble

public double getDouble()

Description copied from class: DataType

Gets the value in the data value descriptor as a double. Throws an exception if the data value is not receivable as a double.

Specified by:

getDouble in interface DataValueDescriptor

Overrides:

getDouble in class DataType

Returns:

The data value as a double.

See Also:

DataValueDescriptor.getDouble()

getBoolean

public boolean getBoolean()

Description copied from class: DataType

Gets the value in the data value descriptor as a boolean. Throws an exception if the data value is not receivable as a boolean.

Specified by:

getBoolean in interface DataValueDescriptor

Overrides:

getBoolean in class DataType

Returns:

The data value as a boolean.

See Also:

DataValueDescriptor.getBoolean()

getString

public java.lang.String getString()

Description copied from interface: DataValueDescriptor

Gets the value in the data value descriptor as a String. Throws an exception if the data value is not a string.

Returns:

The data value as a String.

See Also:

DataValueDescriptor.getString()

getLength

public int getLength()

Description copied from interface: DataValueDescriptor

Gets the length of the data value. The meaning of this is implementation-dependent. For string types, it is the number of characters in the string. For numeric types, it is the number of bytes used to store the number. This is the actual length of this value, not the length of the type it was defined as. For example, a VARCHAR value may be shorter than the declared VARCHAR (maximum) length.

Returns:

The length of the data value

See Also:

DataValueDescriptor.getLength()

getObject

public java.lang.Object getObject()

Description copied from class: DataType

Gets the value in the data value descriptor as a int. Throws an exception if the data value is not receivable as a int.

Specified by:

getObject in interface DataValueDescriptor

Overrides:

getObject in class DataType

Returns:

The data value as a int.

See Also:

DataValueDescriptor.getObject()

getTypeName

public java.lang.String getTypeName()

Description copied from interface: DataValueDescriptor

Get the SQL name of the datatype

Returns:

The SQL name of the datatype

getTypeFormatId

public int getTypeFormatId()

Return my format identifier.

Returns:

The identifier. (A UUID stuffed in an array of 16 bytes).

See Also:

TypedFormat.getTypeFormatId()

isNull

public boolean isNull()

always false for non-nullable columns

Returns:

true if the value is null and false otherwise.

See Also:

Storable.isNull()

writeExternal

public void writeExternal(java.io.ObjectOutput out)
                   throws java.io.IOException

Throws:

java.io.IOException

readExternal

public void readExternal(java.io.ObjectInput in)
                  throws java.io.IOException

Throws:

java.io.IOException

See Also:

Externalizable.readExternal(java.io.ObjectInput)

restoreToNull

public void restoreToNull()

Description copied from interface: Storable

Restore this object to its (SQL)null value.

See Also:

Storable.restoreToNull()

typeCompare

protected int typeCompare(DataValueDescriptor arg)
                   throws StandardException

Description copied from class: NumberDataType

Compare this (not null) to a non-null value.

Specified by:

typeCompare in class NumberDataType

Throws:

StandardException - Thrown on error

cloneValue

public DataValueDescriptor cloneValue(boolean forceMaterialization)

Description copied from interface: DataValueDescriptor

Clone this DataValueDescriptor. Results in a new object that has the same value as this but can be modified independently.

Even though the objects can be modified independently regardless of the value of forceMaterialization, both the clone and the original may be dependent on the store state if forceMaterialization is set to false. An example is if you need to access the value you just read using cloneValue after the current transaction has ended, or after the source result set has been closed.

Parameters:

forceMaterialization - any streams representing the data value will be materialized if true, the data value will be kept as a stream if possible if false

Returns:

A clone of the DataValueDescriptor with the same initial value as this.

See Also:

DataValueDescriptor.cloneValue(boolean)

getNewNull

public DataValueDescriptor getNewNull()

Description copied from interface: DataValueDescriptor

Get a new null value of the same type as this data value.

See Also:

DataValueDescriptor.getNewNull()

setValueFromResultSet

public void setValueFromResultSet(java.sql.ResultSet resultSet,
                         int colNumber,
                         boolean isNullable)
                           throws java.sql.SQLException

Description copied from interface: DataValueDescriptor

Set the value based on the value for the specified DataValueDescriptor from the specified ResultSet.

Parameters:

resultSet - The specified ResultSet.

colNumber - The 1-based column # into the resultSet.

isNullable - Whether or not the column is nullable (No need to call wasNull() if not)

Throws:

java.sql.SQLException - Thrown on error

See Also:

DataValueDescriptor.setValueFromResultSet(java.sql.ResultSet, int, boolean)

setInto

public final void setInto(java.sql.PreparedStatement ps,
           int position)
                   throws java.sql.SQLException

Set the value into a PreparedStatement.

Specified by:

setInto in interface DataValueDescriptor

Overrides:

setInto in class DataType

Throws:

java.sql.SQLException - Error setting value in PreparedStatement

setInto

public final void setInto(java.sql.ResultSet rs,
           int position)
                   throws java.sql.SQLException,
                          StandardException

Set this value into a ResultSet for a subsequent ResultSet.insertRow or ResultSet.updateRow. This method will only be called for non-null values.

Specified by:

setInto in interface DataValueDescriptor

Overrides:

setInto in class DataType

Throws:

java.sql.SQLException - thrown by the ResultSet object

StandardException - thrown by me accessing my value.

setValue

public void setValue(java.lang.String theValue)
              throws StandardException

Description copied from class: DataType

Set the value of this DataValueDescriptor. At DataType level just throws an error lower classes will override

Specified by:

setValue in interface DataValueDescriptor

Overrides:

setValue in class DataType

Parameters:

theValue - The BigDecimal value to set this DataValueDescriptor to

Throws:

StandardException - thrown if string not accepted

setValue

public void setValue(short theValue)

Description copied from class: NumberDataType

Common code to handle converting a short to this value by using the int to this value conversion. Simply calls setValue(int).

Specified by:

setValue in interface DataValueDescriptor

Overrides:

setValue in class NumberDataType

Parameters:

theValue - The value to set this DataValueDescriptor to

setValue

public void setValue(byte theValue)

Description copied from class: NumberDataType

Common code to handle converting a byte to this value by using the int to this value conversion. Simply calls setValue(int).

Specified by:

setValue in interface DataValueDescriptor

Overrides:

setValue in class NumberDataType

Parameters:

theValue - The value to set this DataValueDescriptor to

setValue

public void setValue(int theValue)
              throws StandardException

Description copied from class: DataType

Set the value of this DataValueDescriptor to the given int value At DataType level just throws an error lower classes will override

Specified by:

setValue in interface DataValueDescriptor

Overrides:

setValue in class DataType

Parameters:

theValue - The value to set this DataValueDescriptor to

Throws:

StandardException - if outsideRangeForSmallint

setValue

public void setValue(long theValue)
              throws StandardException

Description copied from class: DataType

Set the value of this DataValueDescriptor to the given long value At DataType level just throws an error lower classes will override

Specified by:

setValue in interface DataValueDescriptor

Overrides:

setValue in class DataType

Parameters:

theValue - The value to set this DataValueDescriptor to

Throws:

StandardException - if outsideRangeForSmallint

setValue

public void setValue(float theValue)
              throws StandardException

Description copied from class: DataType

Set the value of this DataValueDescriptor to the given float value At DataType level just throws an error lower classes will override

Specified by:

setValue in interface DataValueDescriptor

Overrides:

setValue in class DataType

Parameters:

theValue - The value to set this DataValueDescriptor to

Throws:

StandardException - Thrown on error

See Also:

NumberDataValue.setValue(java.lang.Number)

setValue

public void setValue(double theValue)
              throws StandardException

Description copied from class: DataType

Set the value of this DataValueDescriptor to the given double value At DataType level just throws an error lower classes will override

Specified by:

setValue in interface DataValueDescriptor

Overrides:

setValue in class DataType

Parameters:

theValue - The value to set this DataValueDescriptor to

Throws:

StandardException - Thrown on error

See Also:

NumberDataValue.setValue(java.lang.Number)

setValue

public void setValue(boolean theValue)

Description copied from class: DataType

Set the value. At DataType level just throws an error lower classes will override

Specified by:

setValue in interface DataValueDescriptor

Overrides:

setValue in class DataType

Parameters:

theValue - Contains the boolean value to set this to

See Also:

NumberDataValue.setValue(java.lang.Number)

setFrom

protected void setFrom(DataValueDescriptor theValue)
                throws StandardException

Description copied from class: DataType

Set the value of this DataValueDescriptor based on the value of the specified DataValueDescriptor.

Overrides:

setFrom in class DataType

Parameters:

theValue - The DataValueDescriptor that holds the value to which we want to set this DataValueDescriptor's value.

Throws:

StandardException

typePrecedence

public int typePrecedence()

Description copied from class: DataType

Each built-in type in JSQL has a precedence. This precedence determines how to do type promotion when using binary operators. For example, float has a higher precedence than int, so when adding an int to a float, the result type is float. The precedence for some types is arbitrary. For example, it doesn't matter what the precedence of the boolean type is, since it can't be mixed with other types. But the precedence for the number types is critical. The SQL standard requires that exact numeric types be promoted to approximate numeric when one operator uses both. Also, the precedence is arranged so that one will not lose precision when promoting a type.

Specified by:

typePrecedence in interface DataValueDescriptor

Overrides:

typePrecedence in class DataType

Returns:

The precedence of this type.

See Also:

DataValueDescriptor.typePrecedence()

equals

public BooleanDataValue equals(DataValueDescriptor left,
                      DataValueDescriptor right)
                        throws StandardException

The = operator as called from the language module, as opposed to the storage module.

Specified by:

equals in interface DataValueDescriptor

Overrides:

equals in class DataType

Parameters:

left - The value on the left side of the =

right - The value on the right side of the =

Returns:

A SQL boolean value telling whether the two parameters are equal

Throws:

StandardException - Thrown on error

notEquals

public BooleanDataValue notEquals(DataValueDescriptor left,
                         DataValueDescriptor right)
                           throws StandardException

The <> operator as called from the language module, as opposed to the storage module.

Specified by:

notEquals in interface DataValueDescriptor

Overrides:

notEquals in class DataType

Parameters:

left - The value on the left side of the <>

right - The value on the right side of the <>

Returns:

A SQL boolean value telling whether the two parameters are not equal

Throws:

StandardException - Thrown on error

lessThan

public BooleanDataValue lessThan(DataValueDescriptor left,
                        DataValueDescriptor right)
                          throws StandardException

The < operator as called from the language module, as opposed to the storage module.

Specified by:

lessThan in interface DataValueDescriptor

Overrides:

lessThan in class DataType

Parameters:

left - The value on the left side of the <

right - The value on the right side of the < is not.

Returns:

A SQL boolean value telling whether the first operand is less than the second operand

Throws:

StandardException - Thrown on error

greaterThan

public BooleanDataValue greaterThan(DataValueDescriptor left,
                           DataValueDescriptor right)
                             throws StandardException

The > operator as called from the language module, as opposed to the storage module.

Specified by:

greaterThan in interface DataValueDescriptor

Overrides:

greaterThan in class DataType

Parameters:

left - The value on the left side of the >

right - The value on the right side of the >

Returns:

A SQL boolean value telling whether the first operand is greater than the second operand

Throws:

StandardException - Thrown on error

lessOrEquals

public BooleanDataValue lessOrEquals(DataValueDescriptor left,
                            DataValueDescriptor right)
                              throws StandardException

The <= operator as called from the language module, as opposed to the storage module.

Specified by:

lessOrEquals in interface DataValueDescriptor

Overrides:

lessOrEquals in class DataType

Parameters:

left - The value on the left side of the <=

right - The value on the right side of the <=

Returns:

A SQL boolean value telling whether the first operand is less than or equal to the second operand

Throws:

StandardException - Thrown on error

greaterOrEquals

public BooleanDataValue greaterOrEquals(DataValueDescriptor left,
                               DataValueDescriptor right)
                                 throws StandardException

The >= operator as called from the language module, as opposed to the storage module.

Specified by:

greaterOrEquals in interface DataValueDescriptor

Overrides:

greaterOrEquals in class DataType

Parameters:

left - The value on the left side of the >=

right - The value on the right side of the >=

Returns:

A SQL boolean value telling whether the first operand is greater than or equal to the second operand

Throws:

StandardException - Thrown on error

times

public NumberDataValue times(NumberDataValue left,
                    NumberDataValue right,
                    NumberDataValue result)
                      throws StandardException

This method implements the * operator for "smallint * smallint".

Parameters:

left - The first value to be multiplied

right - The second value to be multiplied

result - The result of a previous call to this method, null if not called yet

Returns:

A SQLSmallint containing the result of the multiplication

Throws:

StandardException - Thrown on error

mod

public NumberDataValue mod(NumberDataValue dividend,
                  NumberDataValue divisor,
                  NumberDataValue result)
                    throws StandardException

mod(smallint, smallint)

Specified by:

mod in interface NumberDataValue

Overrides:

mod in class NumberDataType

Parameters:

dividend - The numerator

divisor - The denominator

result - The result of the previous call to this method, null if not called yet.

Returns:

dividend / divisor

Throws:

StandardException - Thrown on error, if result is non-null then its value will be unchanged.

minus

public NumberDataValue minus(NumberDataValue result)
                      throws StandardException

This method implements the unary minus operator for smallint.

Parameters:

result - The result of a previous call to this method, null if not called yet

Returns:

A SQLSmalllint containing the result of the division

Throws:

StandardException - Thrown on error

isNegative

protected boolean isNegative()

This method implements the isNegative method.

Specified by:

isNegative in class NumberDataType

Returns:

A boolean. If this.value is negative, return true. For positive values or null, return false.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

estimateMemoryUsage

public int estimateMemoryUsage()

Description copied from interface: DataValueDescriptor

Estimate the memory usage in bytes of the data value and the overhead of the class.

Returns:

the estimated memory usage