be.SIRAPRISE.client
Class DmlUpdateCommand

java.lang.Object
  be.SIRAPRISE.client.DmlCommand
      be.SIRAPRISE.client.DmlAssignmentCommand
          be.SIRAPRISE.client.DmlSingleAssignmentCommand
              be.SIRAPRISE.client.DmlUpdateCommand

public final class DmlUpdateCommand
extends DmlSingleAssignmentCommand

A DmlUpdateCommand is the command that will replace a tuple with another one in the named relvar (in the target database to which this command will be sent) for the object passed to the constructor. The replaced tuple is determined by the object's getPreUpdateState() return object (which must be of the same class as the object itself), the replacing tuple by the object itself. The command will fail if the replaced tuple is not present in the named relvar, or if the replacing tuple is already present.

Author:

Erwin Smout

Field Summary

static byte

ASSIGNMENTTYPE The byte code identifying the 'UPDATE' assignment type within the messages system

Constructor Summary

DmlUpdateCommand(java.lang.String relvarName, UpdatableDBObject o)
Creates the command object.

Method Summary

java.lang.String	getCommand() Gets the command text
ServerCommand	getServerCommand() Gets the ServerCommand object representing this dml command
java.lang.String	toString()

Methods inherited from class be.SIRAPRISE.client.DmlSingleAssignmentCommand

getRelationText, getRelvarName

Methods inherited from class be.SIRAPRISE.client.DmlAssignmentCommand

getServerAssignmentCommand

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

ASSIGNMENTTYPE

public static final byte ASSIGNMENTTYPE

The byte code identifying the 'UPDATE' assignment type within the messages system

See Also:

Constant Field Values

Constructor Detail

DmlUpdateCommand

public DmlUpdateCommand(java.lang.String relvarName,
                        UpdatableDBObject o)
                 throws NoUpdatesException

Creates the command object. See the DmlAssignmentCommand doc for an explanation of how the relvar's heading and the object's class must correspond to one another.

Parameters:

relvarName - The name of the relvar in which a tuple for the object is to be added.

o - The object for which a tuple is to be added in the named relvar

Throws:

NoUpdatesException - if no attribute value changes at all are detected

java.lang.IllegalArgumentException - If relvarName or o are null, or if relvarName is the zero-length string, or the getPreUpdateState() method of o returns either null or an object that is not of the same class as o.

Method Detail

getCommand

public java.lang.String getCommand()

Description copied from class: DmlCommand

Gets the command text

Specified by:

getCommand in class DmlCommand

Returns:

the command text

getServerCommand

public ServerCommand getServerCommand()

Description copied from class: DmlCommand

Gets the ServerCommand object representing this dml command

Specified by:

getServerCommand in class DmlCommand

Returns:

the ServerCommand object representing this dml command

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object