Is there a Delphi function that will return a unique ID for the computer/terminal/user session? Context: I've got multiple users accessing a common database, and only want each user to see his/her table content (by a SessionID or ComputerID).

Thanks,

Lane Campbell
NW Software

El 12/12/2014 a las 17:34, Lane Campbell escribió:
> 2) Use Now() at startup, to generate a unique character string (with DateTimeToString() function, format
> 'mmddhhmmsszz').

You are using mm for both months and minutes. You shoud use nn for minutes

>
> Any thoughts on preferred alternative, or on the Now() behavior?
>

You can use the following function to create an unique identifier:

{code}
function CreateUniqueID: String;
var
   guid: TGUID;
begin
    CreateGUID(guid);
    Result:= GUIDToString(guid);
end;
{code}


> Thanks,
>
> Lane Campbell
> NW Software
>
> PS: A bit slow on my acronyms today ... what's a "SID"? How do I get it?
>

> {quote:title=Remy Lebeau (TeamB) wrote:}{quote}
> Lane wrote:
> 
> > Is there a Delphi function that will return a unique ID for the
> > computer/terminal/user session?
> 
> No.  And there is no single API function, either.
> 
> > Context: I've got multiple users accessing a common database,
> > and only want each user to see his/her table content (by a
> > SessionID or ComputerID).
> 
> Neither one of those identifies the user.  You would have to use usernames 
> or SIDs instead.
> 
> --
> Remy Lebeau (TeamB)

OK, got that; I'd also looked at the functions getUserName() and getComputerName(), which DO give a result, but not satisfied with the robustness or guarantee of uniqueness. So, looking at a couple other alternatives for creating my unique "sessionID".

(Context: We're using D2010, working with IBObjects on a Firebird DB)

1) Create a single-field table in my DB with an OnInsert trigger to auto-increment the field. This would happen at program start-up, and be cleared when the program shuts down.

2) Use Now() at startup, to generate a unique character string (with DateTimeToString() function, format 
'mmddhhmmsszz'). On the subject of Now(), I tried setting a DateTime or Double variable with Now() and nothing happened ... no error, no result. Now() seems to only work in conjunction with DateTimeToString, or directly settting a DB DateTime field via FieldByName().Value in a TIBOQuery. Any thoughts on what's happening here?

Any thoughts on preferred alternative, or on the Now() behavior?

Thanks,

Lane Campbell
NW Software

PS: A bit slow on my acronyms today ... what's a "SID"? How do I get it?

Lane wrote:

> Is there a Delphi function that will return a unique ID for the
> computer/terminal/user session?

No.  And there is no single API function, either.

> Context: I've got multiple users accessing a common database,
> and only want each user to see his/her table content (by a
> SessionID or ComputerID).

Neither one of those identifies the user.  You would have to use usernames 
or SIDs instead.

--
Remy Lebeau (TeamB)