2007. április 30., hétfő

How to copy records to the same table


Problem/Question/Abstract:

I need to copy a record in a dBase table to the same table and just change a value or two. I know that I can copy the hard way read all the fields into a record then write it back out.

Answer:

Solve 1:

var
  SourceQueryFieldName: string;
begin
  QueryDestination.Open;
  QuerySource.Open;
  QueryDestination.Insert;
  for FieldLoop := 0 to QuerySource.FieldCount - 1 do
  begin
    SourceQueryFieldName := DataBaseQuerySource.Fields[FieldLoop].FieldName;
    try
      QueryDestination[SourceQueryFieldName] := QuerySource[SourceQueryFieldName];
    except
      {Field not Found}
    end;
  end;
  QueryDestination.Post;
  QueryDestination.Close;
  QuerySource.Close;
end;

Solve 2:

I actually prefer code that reads each field and writes it to the new record like this:

procedure CopyRecord(tbl: TTable);
var
  I: Integer;
  tblTmp: TTable;
begin
  blTmp := TTable.Create(nil);
  try
    tblTmp.DatabaseName := tbl.DatabaseName;
    tblTmp.TableName := tbl.TableName;
    tblTmp.Open;
    ttblTmp.GotoCursor(Src);
    tbl.Insert;
    try
      for I := 0 to T.FieldCount - 1 do
        tbl.Fields[I].Assign(tblTmp.Fields[I]);
    except
      tbl.Cancel;
      raise;
    end;
  finally
    tblTmp.Free;
  end;
end;

But you can also do it like this:

procedure CopyRecord(const FromTable: TTable);
begin
  dbiInsertRecord(FromTable.Handle, dbiNoLock, FromTable.ActiveBuffer);
end;

Nincsenek megjegyzések:

Megjegyzés küldése