Delphi - Loading FDMEMTable

Question

Sorry, not simple for a new Delphi'er

In the code below, how do I move the results to a fdmemtable?

• Do I have to loop-add each record or can the memtable just be set equal to the recordset using a function/procedure?

• Or, can the results be sent directly to a fdmemtable?

My problem with this code is the cmd.execute is returning a recordset but that is not the type the memTable is looking for. Need assist.

procedure TForm1.btnADReadClick(Sender: TObject);
var // SQLad,DOMAINad,USERad:string;
    t:_recordset;
begin
  DOMAINad:= QuotedStr('LDAP://')+DOMAINad;
  //listbox1.Clear;
  try
    datamodule1.connADOldap.ConnectionString := 'Provider=ADsDSOObject';
    cmd.Connection:=datamodule1.connADOldap;
    datamodule1.connADOldap.Connected:=true;
    SQLad:='select cn,distinguishedname from '+DOMAINad+' where objectClass='
    //+Quotedstr('*');
    +Quotedstr('user');
    //
    cmd.CommandText:=SQLad;
    cmd.Properties.Item['Page Size'].Value:=40;
    //t:=cmd.Execute;
    datamodule1.FDMemTableADResults:=cmd.Execute;
  except
   on exception do showmessage('Error');
  end;

end;

Answer 1

This is simpler if you use a TADODataSet instead

  ADODataSet1.ConnectionString := 'Provider=ADsDSOObject';
  ADODataSet1.CommandText := 'select cn, distinguishedname from ''LDAP://HOME'' where objectClass=''*''';
  ADODataSet1.Open;
  ADODataSet1.Recordset.PageSize :=40; // << Edit
  FDMemTable1.CopyDataSet(ADODataSet1, [coStructure, coRestart, coAppend]);
  FDMemTable1.Open;

Answer 2

You can use CloneCursor

procedure CloneCursor(ASource: TFDDataSet; AReset: Boolean = False;  AKeepSettings: Boolean = False); 

You make the call from the MemTable and pass it the query. This will share the data between the two objects without needing to copy it row by row/field by field.

MemTable.CloneCursor(QueryDataSet, false, false);

You didn't say why you wanted the data in a MemTable vs. a TFDQuery object. There are times where this is useful, but if your only reason is for getting the results of the query back simply use the returned TFDQuery object. Both objects are almost identical in their use. The TFDQuery Object can stay connected to the database so that changes you make can be pushed back into the database.

Based on your comment about Page size you should also look at the FetchOptions CursorKind and Mode properties. These help control how much data is returned into the QueryObject at one time. These can be set either on the connection or the FireDAC query object. I normally use a Static cursor with All results returned. If you query can return millions of rows that is not a good choice but I'm usually only dealing with a few thousand rows. ADO has similar properties.

Query.FetchOptions.CursorKind := ckStatic;
Query.FetchOptions.Mode := fmAll;