org.apache.derby.iapi.types
Interface Orderable

All Known Subinterfaces:
BinaryOrderable, BitDataValue, BooleanDataValue, ConcatableDataValue, Conglomerate, DataValueDescriptor, DateTimeDataValue, NumberDataValue, RefDataValue, RowLocation, StringDataValue, UserDataValue
All Known Implementing Classes:
DataType, GenericConglomerate, Heap, HeapRowLocation, NumberDataType, SQLBinary, SQLBoolean, SQLChar, SQLDate, SQLRef, SQLTime, SQLTimestamp, UserType

public interface Orderable

The Orderable interface represents a value that can be linearly ordered.

Currently only supports linear (<, =, <=) operations. Eventually we may want to do other types of orderings, in which case there would probably be a number of interfaces for each "class" of ordering.

The implementation must handle the comparison of null values. This may require some changes to the interface, since (at least in some contexts) comparing a value with null should return unknown instead of true or false.


Field Summary
static int ORDER_OP_EQUALS
          Ordering operation constant representing '='
static int ORDER_OP_GREATEROREQUALS
          Ordering operation constant representing '>='
static int ORDER_OP_GREATERTHAN
          Ordering operation constant representing '>'
static int ORDER_OP_LESSOREQUALS
          Ordering operation constant representing '<='
static int ORDER_OP_LESSTHAN
          Ordering operation constant representing '<'
 

Field Detail

ORDER_OP_LESSTHAN

public static final int ORDER_OP_LESSTHAN
Ordering operation constant representing '<'

See Also:
Constant Field Values

ORDER_OP_EQUALS

public static final int ORDER_OP_EQUALS
Ordering operation constant representing '='

See Also:
Constant Field Values

ORDER_OP_LESSOREQUALS

public static final int ORDER_OP_LESSOREQUALS
Ordering operation constant representing '<='

See Also:
Constant Field Values

ORDER_OP_GREATERTHAN

public static final int ORDER_OP_GREATERTHAN
Ordering operation constant representing '>'

See Also:
Constant Field Values

ORDER_OP_GREATEROREQUALS

public static final int ORDER_OP_GREATEROREQUALS
Ordering operation constant representing '>='

See Also:
Constant Field Values


Apache Derby V10.0 Engine Documentation - Copyright © 1997,2004 The Apache Software Foundation or its licensors, as applicable.