net.ontopia.persistence.query.sql
Class SQLNull

java.lang.Object
  net.ontopia.persistence.query.sql.SQLNull

All Implemented Interfaces:

SQLValueIF

public class SQLNull
extends java.lang.Object
implements SQLValueIF

INTERNAL: SQL value: null. Represents the SQL null value.

Field Summary

protected java.lang.String	alias
protected FieldHandlerIF	fhandler
protected java.lang.Class	vtype

Fields inherited from interface net.ontopia.persistence.query.sql.SQLValueIF

COLUMNS, FUNCTION, NULL, PARAMETER, PRIMITIVE, TUPLE, VERBATIM

Constructor Summary

SQLNull()

Method Summary

boolean	equals(java.lang.Object obj)
java.lang.String	getAlias() INTERNAL: The column alias to use if this value is included in the projection.
int	getArity() INTERNAL: Returns the [column] arity of the value.
FieldHandlerIF	getFieldHandler() INTERNAL: Returns the field handler for the columns.
SQLValueIF	getReference() INTERNAL: Returns the referenced value if one exists.
int	getType() INTERNAL: Returns the value class type.
int	getValueArity() INTERNAL: Returns the value arity of the value.
java.lang.Class	getValueType() INTERNAL: Returns the value type.
int	hashCode()
boolean	isReference() INTERNAL: Returns true if this value is a reference to another.
void	setAlias(java.lang.String alias) INTERNAL: Sets the column alias.
void	setFieldHandler(FieldHandlerIF fhandler) INTERNAL: Sets the field handler for the value.
void	setValueType(java.lang.Class vtype) INTERNAL: Sets the value type.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

alias

protected java.lang.String alias

vtype

protected java.lang.Class vtype

fhandler

protected FieldHandlerIF fhandler

Constructor Detail

SQLNull

public SQLNull()

Method Detail

getType

public int getType()

Description copied from interface: SQLValueIF

INTERNAL: Returns the value class type. The type is represented by one of the constants in the SQLValueIF interface.

Specified by:

getType in interface SQLValueIF

getArity

public int getArity()

Description copied from interface: SQLValueIF

INTERNAL: Returns the [column] arity of the value. The number represents the number of "columns" the value spans, i.e. its composite width.

Specified by:

getArity in interface SQLValueIF

getValueArity

public int getValueArity()

Description copied from interface: SQLValueIF

INTERNAL: Returns the value arity of the value. This number refers to the number of nested values this value contains including itself. Most values therefore have a value arity of 1. Nested values may have an arity higher than 1. SQLTuple is currently the only nested value type.

Specified by:

getValueArity in interface SQLValueIF

getAlias

public java.lang.String getAlias()

Description copied from interface: SQLValueIF

INTERNAL: The column alias to use if this value is included in the projection. The SQL select syntax is typically like "select value as from foo".

Specified by:

getAlias in interface SQLValueIF

setAlias

public void setAlias(java.lang.String alias)

Description copied from interface: SQLValueIF

INTERNAL: Sets the column alias.

Specified by:

setAlias in interface SQLValueIF

isReference

public boolean isReference()

Description copied from interface: SQLValueIF

INTERNAL: Returns true if this value is a reference to another.

Specified by:

isReference in interface SQLValueIF

getReference

public SQLValueIF getReference()

Description copied from interface: SQLValueIF

INTERNAL: Returns the referenced value if one exists.

Specified by:

getReference in interface SQLValueIF

getValueType

public java.lang.Class getValueType()

Description copied from interface: SQLValueIF

INTERNAL: Returns the value type.

Specified by:

getValueType in interface SQLValueIF

setValueType

public void setValueType(java.lang.Class vtype)

Description copied from interface: SQLValueIF

INTERNAL: Sets the value type.

Specified by:

setValueType in interface SQLValueIF

getFieldHandler

public FieldHandlerIF getFieldHandler()

Description copied from interface: SQLValueIF

INTERNAL: Returns the field handler for the columns.

Specified by:

getFieldHandler in interface SQLValueIF

setFieldHandler

public void setFieldHandler(FieldHandlerIF fhandler)

Description copied from interface: SQLValueIF

INTERNAL: Sets the field handler for the value.

Specified by:

setFieldHandler in interface SQLValueIF

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object