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(*
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* Firebird UDR Support (fbudrtestbed). The fbudr components provide a set of
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* Pascal language bindings for the Firebird API in support of server
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* side User Defined Routines (UDRs). The fbudr package is an extension
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* to the Firebird Pascal API.
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*
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* The contents of this file are subject to the Initial Developer's
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* Public License Version 1.0 (the "License"); you may not use this
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* file except in compliance with the License. You may obtain a copy
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* of the License here:
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*
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* http://www.firebirdsql.org/index.php?op=doc&id=idpl
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*
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* Software distributed under the License is distributed on an "AS
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* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
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* implied. See the License for the specific language governing rights
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* and limitations under the License.
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*
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* The Initial Developer of the Original Code is Tony Whyman.
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*
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* The Original Code is (C) 2021 Tony Whyman, MWA Software
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* (http://www.mwasoftware.co.uk).
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*
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* All Rights Reserved.
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*
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* Contributor(s): ______________________________________.
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*
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*)
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unit udr_test04;
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{$IFDEF MSWINDOWS}
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{$DEFINE WINDOWS}
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{$ENDIF}
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{$IFDEF FPC}
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{$mode delphi}
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{$codepage UTF8}
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{$interfaces COM}
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{$ENDIF}
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interface
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uses
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Classes, SysUtils, IB, FBUDRController, FBUDRIntf;
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{This unit provides the implementation of a UDR trigger and is used
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to test out various aspects of the TFBUDRTrigger class. Note that each class is
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registered with the FBUDRController at initialization time.}
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type
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{This test adds an extra column to EMPLOYEE table to work with with an update before trigger.
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This is OLD_PHONE_EXT. The trigger checks to see if the Phone_Ext has been updated and, if so, the old
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value is saved in OLD_PHONE_EXT.
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Alter Table EMPLOYEE Add PREVIOUS_PHONE_EXT VarChar(4);
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Create or Alter Trigger MyEmployeeUpdate Active Before Update On EMPLOYEE
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external name 'fbudrtests!my_employee_update'
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engine udr;
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}
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{ TMyEmployeeUpdateTrigger }
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TMyEmployeeUpdateTrigger = class(TFBUDRTrigger)
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public
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procedure BeforeTrigger(context: IFBUDRExternalContext;
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TriggerMetaData: IFBUDRTriggerMetaData;
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action: TFBUDRTriggerAction;
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OldParams: IFBUDRInputParams;
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NewParams: IFBUDROutputData); override;
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end;
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implementation
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{ TMyEmployeeUpdateTrigger }
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procedure TMyEmployeeUpdateTrigger.BeforeTrigger(
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context: IFBUDRExternalContext; TriggerMetaData: IFBUDRTriggerMetaData;
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action: TFBUDRTriggerAction; OldParams: IFBUDRInputParams;
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NewParams: IFBUDROutputData);
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begin
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if (TriggerMetaData.getTriggerType <> ttBefore) or (action <> taUpdate) then
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raise Exception.CreateFmt('%s should be an update before trigger',[Name]);
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if OldParams.ByName('PHONE_EXT').AsString <> NewParams.ByName('PHONE_EXT').AsString then
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NewParams.ByName('PREVIOUS_PHONE_EXT').AsString := OldParams.ByName('PHONE_EXT').AsString;
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end;
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initialization
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FBRegisterUDRTrigger('my_employee_update', TMyEmployeeUpdateTrigger);
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end.
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