Re: VB6 Login Form to SQL Server

From: DavidM (spam_at_spam.net)
Date: 12/03/04 

Date: Fri, 3 Dec 2004 10:22:42 -0600

Thank you -- I'll add to last login and last database to registry and
pre-fill textbox each time Login form is displayed. I'll also change my
events around.

"Mark J. McGinty" <mmcginty@spamfromyou.com> wrote in message
news:e0rm44I2EHA.2112@TK2MSFTNGP15.phx.gbl...
>
> "Wart" <nospamWart@epix.net> wrote in message
> news:%23Qs8vzx1EHA.936@TK2MSFTNGP12.phx.gbl...
>> David,
>> Three options.
>> 1) Use the Lost Focus event
>> 2) Don't use theChange or Lost Focus and put a "Login" button on the form
>> 3) In the Change Event, call a routine that will validate that an octet
>> has been entered. If not, do nothing. If so, try to login.
>> HTH,
>> CF
>> "DavidM" <spam@spam.net> wrote in message
>> news:u2mGYwo1EHA.4004@tk2msftngp13.phx.gbl...
>>> Well, I got my login form to work.
>>>
>>> It currently displays a textbox for server, username, password, and a
>>> combo for databases.
>>>
>>> What I have done is within the server, username, and password Change
>>> Event, coded a routine to see if there is data in the textbox. If there
>>> is, it attempts to call the LoadDatabases routine to attempt to connect
>>> to DB using this information simply to execute a "SELECT * FROM
>>> sysdatabases" using the master database. Once combo is filled, I
>>> destroy the connection and, once the user has selected all four items on
>>> the form, the "OK" button will become enabled.
>>>
>>> Everything works fine except I do have one problem.
>>>
>>> If I fill in the textboxes using username and password first... and then
>>> go to the server box and try and enter an IP address... the change event
>>> is called for each keystroke. There is a 10 second delay between
>>> keystrokes as ADO tries to connect to the TCP/IP address (even though it
>>> is incomplete until the user enters the last octet.) I then added a
>>> routine to validate the "server" box for a valid TCPIP... which makes
>>> the keystrokes much faster until the last octet is entered.
>
> Attempting to open a connection without knowing with certainty that the
> server address and credentials are complete, is a total waste of resources
> and connectivity. It may seem adequate responsive once the server is
> correct, with only a single user, but if you're trying to tender
> credentials on every keystroke in the user or password inputs... it won't
> take many users to incur significant but needless load.
>
> Your program may need to be dynamic, but users tend to connect to only a
> small number of servers in real life, so do them a favor: when you
> successfully connect to a server, store its address in the registry, or
> persist it to XML, and then load a combo box with them for the user to
> pick from.
>
> As for an event to drive the connection, I like to process KeyPress, and
> attempt the connection when the user presses the Enter in any of those 3
> inputs, if each contains an entry. If not, Enter acts like Tab, moving
> focus to the next input. LostFocus (as has been suggested) is pretty good
> too, but it doesn't seem as intuitive to connect when you tab away from an
> input. Enter is the traditional "send info for processing" key.
>
> Back to doing the user a favor, chances are very good that the user will
> want to connect to the same database that they used last session, so
> again, store it in the registry and default to it. Hard to seriously call
> such a simple measure "heuristic" but that's how it's usually perceived.
>
>
> -Mark
>
>
>
>
>
>>> Anyway -- does anyone know a better way around this?
>>>
>>> My routine is currently relying on a valid TCP/IP address. If someone
>>> tries to type in a server name... well, the validation routine will
>>> return false and the "OK" button will never enable.
>>>
>>> As long as the servername is valid from the get-go, all else seems to be
>>> pretty quick.
>>>
>>> Anyone know of anything else I should try?
>>>
>>> Perhaps change the txtServer event from "Change" to "Lost Focus"?
>>>
>>>
>>>
>>> "Jeff Johnson [MVP: VB]" <i.get@enough.spam> wrote in message
>>> news:eqckizl1EHA.4072@TK2MSFTNGP10.phx.gbl...
>>>>
>>>> "DavidM" <spam@spam.net> wrote in message
>>>> news:e6ncSzj1EHA.3336@TK2MSFTNGP11.phx.gbl...
>>>>
>>>>> Does anyone know a standard way of displaying all databases a
>>>>> specified login has access to on SQL Server?
>>>>
>>>> You could use ADOX, or the OpenSchema method in ADO, or you could open
>>>> a recordset with
>>>>
>>>> SELECT * FROM INFORMATION_SCHEMA.TABLES
>>>>
>>>> if the SQL Server is 7.0 or later.
>>>>
>>>
>>>
>>
>>
>
>