org.vanilladb.core.sql

Class VarcharConstant

java.lang.Object

org.vanilladb.core.sql.Constant

org.vanilladb.core.sql.VarcharConstant

All Implemented Interfaces:

Comparable<Constant>

public class VarcharConstant
extends Constant

The class that wraps Java strings as database constants.

Constructor Summary

Constructors

Constructor and Description
VarcharConstant(byte[] v, Type type)
VarcharConstant(String s) Create a constant by wrapping the specified string.
VarcharConstant(String s, Type type)

Method Summary

Modifier and Type	Method and Description
Constant	add(Constant c) Adds this constant a value specified by another constant.
byte[]	asBytes() Each char is encoded using the VarcharType.CHAR_SET.
Object	asJavaVal() Unwraps the string and returns it.
Constant	castTo(Type type) Casts this constant to the specified type.
int	compareTo(Constant c)
Constant	div(Constant c) Divides this constant by a value specified by another constant.
boolean	equals(Object obj) Indicates whether some other object is Constant object and its value equal to this one.
Type	getType() Returns the type corresponding to this constant.
int	hashCode()
Constant	mul(Constant c) Multiplies this constant by a value specified by another constant.
int	size() Return the number of bytes required to encode this constant.
Constant	sub(Constant c) Subtracts a value specified by another constant from this constant.
String	toString()

Methods inherited from class org.vanilladb.core.sql.Constant

defaultInstance, newInstance

Methods inherited from class java.lang.Object

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

Constructor Detail

VarcharConstant

public VarcharConstant(String s)

Create a constant by wrapping the specified string.

Parameters:

s - the string value

VarcharConstant

public VarcharConstant(byte[] v,
                       Type type)

VarcharConstant

public VarcharConstant(String s,
                       Type type)

Method Detail

getType

public Type getType()

Description copied from class: Constant

Returns the type corresponding to this constant.

Specified by:

getType in class Constant

Returns:

the type of the constant

asJavaVal

public Object asJavaVal()

Unwraps the string and returns it.

Specified by:

asJavaVal in class Constant

Returns:

the Java value of the constant

See Also:

Constant.asJavaVal()

asBytes

public byte[] asBytes()

Each char is encoded using the VarcharType.CHAR_SET.

Specified by:

asBytes in class Constant

Returns:

the byte array of the constant

size

public int size()

Description copied from class: Constant

Return the number of bytes required to encode this constant.

Specified by:

size in class Constant

Returns:

the size of the this constant

castTo

public Constant castTo(Type type)

Description copied from class: Constant

Casts this constant to the specified type. Does not support casting from a string constant to a numeric constant.

Specified by:

castTo in class Constant

Parameters:

type - the type the caller intends to cast to

Returns:

the constant casted to the specified type

equals

public boolean equals(Object obj)

Indicates whether some other object is Constant object and its value equal to this one.

Overrides:

equals in class Object

compareTo

public int compareTo(Constant c)

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

add

public Constant add(Constant c)

Description copied from class: Constant

Adds this constant a value specified by another constant. Does not support adding value to a string constant. Automatic type upgrade will be done during the arithmetic.

Specified by:

add in class Constant

Parameters:

c - constant whose value will be added

Returns:

a constant with value equals to the sum of the value of this constant and another constant

sub

public Constant sub(Constant c)

Description copied from class: Constant

Subtracts a value specified by another constant from this constant. Does not support adding value to a string constant. Automatic type upgrade will be done during the arithmetic.

Specified by:

sub in class Constant

Parameters:

c - constant whose value will be substracted from

Returns:

a constant with value equals to the value of this constant subtracted from that of another constant

div

public Constant div(Constant c)

Description copied from class: Constant

Divides this constant by a value specified by another constant. Does not support adding value to a string constant. Automatic type upgrade will be done during the arithmetic.

Specified by:

div in class Constant

Parameters:

c - divider

Returns:

a constant with value equals to the value of this constant divided by that of another constant

mul

public Constant mul(Constant c)

Description copied from class: Constant

Multiplies this constant by a value specified by another constant. Does not support adding value to a string constant. Automatic type upgrade will be done during the arithmetic.

Specified by:

mul in class Constant

Parameters:

c - multiplier

Returns:

a constant with value equals to the value of this constant multiplied by that of another constant