2010. október 1., péntek

Ms Access LastinsertID


Problem/Question/Abstract:

Ever wondered how to retrieve the last insert id in MsAccess, of the autoincrement field from a table.

Answer:

We have a table in MsAccess like :

Test, Fields (id=autoinc, name=text);

First we have to have a function like the one below :

function GetLastInsertID: integer;
begin

  // datResult = TADODataSet

  datResult.Active := False;
  datResult.CommandText := 'select @@IDENTITY as [ID]';
  datResult.Active := True;

  Result := datResult.FieldByName('id').AsInteger;

  datResult.Active := False;

end;

Now before getting the last inserted record record id = autoincrement field, in other words calling the above function. You have to do a SQL insert like the following

procedure InsertRec;
begin

  // datCommand = TADOCommand

  datCommand.CommandText := 'insert into [test] ( [name] ) values ( "Test" )';
  datCommand.Execute;

end;

Now if we like to know which is the last autoinc value ( notice that the getlastinsertid proc. only works after the insertrec proc)

procedure Test;
begin
  InsertRec;
  Showmessage(format('lastinsertid : %d', [GetLastInsertID]));
end;

Hope you can make this work, it works for me, any questions feel free to ask

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