Componentes.Terceros.RemObjects/internal/5.0.29.665/1/Data Abstract for Delphi/Samples/Dynamic SQL/DynSQLService_Impl.pas

unit DynSQLService_Impl;

{----------------------------------------------------------------------------}
{ This unit was automatically generated by the RemObjects SDK after reading  }
{ the RODL file associated with this project .                               }
{                                                                            }
{ This is where you are supposed to code the implementation of your objects. }
{----------------------------------------------------------------------------}

interface

uses
  {vcl:} Classes, SysUtils,
  {RemObjects:} uROClientIntf, uROTypes, uROServer, uROServerIntf, uROSessions,
  {Ancestor Implementation:} DataAbstractService_Impl,
  {Used RODLs:} DataAbstract4_Intf, uDAInterfaces,
  {Generated:} DynSQLLibrary_Intf,  uDAClasses, uDADelta,
  uDABin2DataStreamer, uDADataStreamer, uDAScriptingProvider,
  uDABusinessProcessor;

type
  { TDynSQLService }
  TDynSQLService = class(TDataAbstractService, IDynSQLService)
    DataStreamer: TDABin2DataStreamer;
    BusinessProcessor: TDABusinessProcessor;
    Schema: TDASchema;
    procedure BusinessProcessorGenerateSQL(Sender: TDABusinessProcessor;
      ChangeType: TDAChangeType; const ReferencedStatement: TDAStatement;
      const aDelta: IDADelta; var SQL: String);
    procedure BusinessProcessorProcessError(Sender: TDABusinessProcessor;
      aChangeType: TDAChangeType; aChange: TDADeltaChange;
      const aCommand: IDASQLCommand; var CanRemoveFromDelta: Boolean;
      Error: Exception);
    procedure BusinessProcessorAfterProcessChange(
      Sender: TDABusinessProcessor; aChange: TDADeltaChange;
      Processed: Boolean; var CanRemoveFromDelta: Boolean);
  private
    procedure Log(aStr: string);
    function _GetConnection: IDAConnection;
  protected
    function MyUpdateData(const aTableName: String; const Delta: Binary): Binary;
  end;

implementation

{$R *.dfm}
uses
  {Generated:} DynSQLLibrary_Invk, DynSQLServerMain, Dialogs, TypInfo;

procedure Create_DynSQLService(out anInstance: IUnknown);
begin
  anInstance := TDynSQLService.Create(nil);
end;

{ TDynSQLService }

function TDynSQLService._GetConnection: IDAConnection;
begin
  Result := DynSQLServerMainForm.DAConnectionManager.NewConnection('ADO');
end;

procedure TDynSQLService.Log(aStr: string);
begin
  DynSQLServerMainForm.Log(aStr);
end;

function TDynSQLService.MyUpdateData(const aTableName: String; const Delta: Binary): Binary;
var
  conn: IDAConnection;
  realdelta: IDADelta;
  i: integer;
  sql: string;
  fOldDeltaname: string;
begin
  Log('');
  Log('');
  // Opens a connection
  conn := _GetConnection;

  // Creates a delta object
  realdelta := NewDelta('tempDelta');

  // Converts the binary stream we just received.
  DataStreamer.Initialize(Delta, aiReadFromBeginning);
  try
    fOldDeltaname:=DataStreamer.DeltaNames[0];
    DataStreamer.ReadDelta(DataStreamer.DeltaNames[0], realdelta);
  finally
    DataStreamer.Finalize;
  end;

  if (aTableName = '') or (realdelta.Count=0) then begin
    // Builds a fake SQL string for updating and displays it
    sql := 'Updating query "' + DataStreamer.DeltaNames[0] + '", fields ';

    for i := 0 to (realdelta.LoggedFieldCount - 1) do
      sql := sql + realdelta.LoggedFieldNames[i] + '(' + GetEnumName(TypeInfo(TDADataType), Ord(realdelta.LoggedFieldTypes[i])) + '), ';

    sql := Copy(sql, 1, Length(sql) - 2);

    Log(sql);
  end
  else begin
    realDelta.LogicalName:= aTableName;
    // setup of ReferencedDataset used in BP.ProcessDelta
    with Schema.Datasets.DatasetByName(BusinessProcessor.ReferencedDataset),Statements[0] do begin
      TargetTable:=aTableName;
      ColumnMappings.Clear;
      Fields.Clear;
      for i:=0 to realdelta.LoggedFieldCount-1 do begin
        Fields.Add(realdelta.LoggedFieldNames[i],realdelta.LoggedFieldTypes[i]);
        with ColumnMappings.Add do begin
          DatasetField:= realdelta.LoggedFieldNames[i];
          TableField:= realdelta.LoggedFieldNames[i];
          SQLOrigin:= realdelta.LoggedFieldNames[i];
        end;
      end;
    end;
    BusinessProcessor.ProcessDelta(conn,realdelta);
  end;

  Result:=Binary.Create;
  realdelta.LogicalName:=fOldDeltaname;
  DataStreamer.Initialize(Result, aiWrite);
  try
    DataStreamer.WriteDelta(realdelta);
  finally
    DataStreamer.Finalize;
  end;
end;

procedure TDynSQLService.BusinessProcessorGenerateSQL(
  Sender: TDABusinessProcessor; ChangeType: TDAChangeType;
  const ReferencedStatement: TDAStatement; const aDelta: IDADelta;
  var SQL: String);
begin
  Log('Generated SQL: '+SQL);
end;

procedure TDynSQLService.BusinessProcessorProcessError(
  Sender: TDABusinessProcessor; aChangeType: TDAChangeType;
  aChange: TDADeltaChange; const aCommand: IDASQLCommand;
  var CanRemoveFromDelta: Boolean; Error: Exception);
begin
  Log('Error during processing change (RecID=' + IntToStr(aChange.RecID)+')');
  Log(Error.Message);
end;

procedure TDynSQLService.BusinessProcessorAfterProcessChange(
  Sender: TDABusinessProcessor; aChange: TDADeltaChange;
  Processed: Boolean; var CanRemoveFromDelta: Boolean);
begin
  if Processed then
    Log('Change (RecID=' + IntToStr(aChange.RecID) +') is processed')
  else
    Log('Change (RecID=' + IntToStr(aChange.RecID) +') isn''t processed');
end;

initialization
  TROClassFactory.Create('DynSQLService', Create_DynSQLService, TDynSQLService_Invoker);

finalization

end.