Create and destroy DBISAM in-memory tables as needed

Problem/Question/Abstract:

When I have deleted an in-memory table and I want to create it again, I get an error message that I have duplicate field names. What is wrong here?

Answer:

This automatically creates and destroys memory tables as needed. Use these procedures to open and close your tables.

procedure OpenTbl(Tbl: TDBISAMTable);
begin
  if (Tbl.Active = False) then
  begin
    with Tbl do
    begin
      try
        if not (Exists) and InMemory then
          CreateTable;
        Open;
        First;
      except
        raise EOpenTable.Create('Error: couldn' t open table.('+Tbl.TableName+':
          '+Tbl.Name+')');
      end;
    end;
  end;
end;

procedure CloseTbl(Tbl: TDBISAMTable);
begin
  with Tbl do
  begin
    if (Active = True) then
    begin
      if (state = dsInsert) or (state = dsEdit) then
      begin
        try
          Post;
        except
          Cancel;
        end;
      end;
      Tbl.FlushBuffers;
      Close;
      if InMemory then
      begin
        try
          DeleteTable;
        except
          { ... }
        end;
      end;
    end;
  end;
end;