Issue with TADODataSet on Delphi 10.1 Berlin. Query hangs

Question

I am trying to operate an TADODataSet in a program on Delphi 10.1 Berlin

Here is my code:

rsGrid.Connection := MyADOConn;
rsGrid.CommandType := cmdText;
rsGrid.CommandText := 'my_StoredProc 100';
rsGrid.IndexName := 'ObjectID';

rsGrid.Active := True; //***** Showstopper here! *****// 

while not rsGrid.Eof do
begin
   Memo1.Lines.Add(rsGrid.FieldByName('ObjectID').AsString);
   rsGrid.Next;
end;

The Connection property of the DataSet sets up as follows:

function TMainForm.MyADOConn: TADOConnection;
begin
    Result := TADOConnection.Create(nil);
    with Result do
    begin
        ConnectionString := 'Provider=SQLNCLI11.1;Persist Security Info=False;User ID=user15;Password=mypassword;Initial Catalog=MyDB;Data Source=my.server.com;Initial File Name="";Server SPN=""'';
        KeepConnection := True;
        IsolationLevel := ilCursorStability;
        Mode := cmUnknown;
        LoginPrompt := False;
        Connected := True;
    end;
end;

The database is SQL Server 2012, so I tried to run it with SQL Server Native Client 10 and 11 (Provider=SQLNCLI10.1 and Provider=SQLNCLI11.1 respectively).

I plan to use this TADODataSet later with a Grid component (via TDataSet) but I couldn't make this thing working In XE8, Seattle and now Berlin. It just hangs on rsGrid.Active := True. I also tried rsGrid.Open but it doesn't work as well.

At the same time it perfectly compiles and executes on my XE4. What am I doing wrong in Berlin?

Pretty sure it's not related to your problem, but the way you're creating the connection object is screaming out memory leak. Every time you call that function MyADOConn it creates a new connection instance, and the only reference you keep to it is inside of rsGrid. I hope you're freeing it somewhere later, but even if so, the design is still majorly flawed and can still cause a big leak. — Jerry Dodge
Thanks for mentioning that Jerry, but here is just an example. In my real app the connection object is constructed and freed properly ;) Proven by MadExcept. — Interface Unknown
If you replace your TAdoDataSet with a TAdoQuery, can you successfully open it in the IDE using the Object Inspector? — MartynA
@MartynA, In design-time I can perfectly open both TADODataSet and TADOQuery in Object Inspector. The only problem appears at run-time. — Interface Unknown
In that case, I think it's likely yo be something that only you can debug,but you should be able to easily find out exactly where it is hanging at run-time. Make sure your project has "Use debug DCUs" checked under your project's Debug options, then trace into rsGrid.Active := True. — MartynA

Interface Unknown Interface Unknown · Accepted Answer · 2016-05-30T08:33:02

Here is what happened. I am posting it as the answer, so it may help others who port the code from earlier versions of Delphi XE (prior to XE8) to XE8/Seattle/Berlin.

For some reason when you port the forms with TADODataSet component on it, it loses some key attribute(s). In other words, when transferred the component misses some attributes (i.e. LockType := ltOptimistic) which are important in my particular case.

How To Make It Work
To get your code back to life, simply re-place the TADODataSet component on your Form (delete it and place a new one).

Issue with TADODataSet on Delphi 10.1 Berlin. Query hangs

1 Answers