Assincronous processes

[dinacio]

Hi everybody! I'm new in VB.

I want to process SQL store procedure in the SQL server and another VB functions without freezing my terminal.
When processes a SQL store procedure I can't do nothing until it ends.
How can I resolve this.

Thank you!
dinacio

[Iain17]

I am afraid this is a little easier said than done.

First off you will need to create an ActiveX exe project that calls the Stored procedure. And i am afraid it isn't even quite as simple as that.

You need to call a sub in the AX exe, that starts a timer, and that's it, nothing more. This means that the sub initialises a timer, and passes control back to your VB app.

When the timer event fires in your AX exe, you call the sub that calls the Stored procedure. This way, the sub is called from the AX exe, and it can run in the background, as control has already been passed back to your VB program.

Then in your sub that calls the Stored Procedure, you can raise an event back to VB after the work has been done, to let it know that it has done. You can handle this event like any normal event, e.g, click event.

I hope this has shed some light on the matter.

[Sam Finch]

oK, I think I get what you're asking, but you've asked it in a very complicated way.


By the sound of it you have a procedure that takes a long time to run and when you run it the program freezes until it finishes.

The answer to this is a Command called DoEvents, what this does is stops the procedure briefly and lets VB handle all the other stuff it needs to do (like repanting the form, allowing the user to move it with the caption bar, letting you click buttons, etc. put the DoEvents command inside any large loops. For Example

Dim i As Integer

For i = 1 To 10000

    'Process a record or something that you have to do 10000 times
    Call ProcessRecor(i)

Next i

will freeze up your app until it finishes, but

Dim i As Integer

For i = 1 To 10000

    'Process a record or something that you have to do 10000 times
    Call ProcessRecor(i)

    'Allow the App to do anything that needs doing
    DoEvents

Next i

Won't freeze up your app, hope this helps.

[Lafor]

Lain17...

That is very goooodd!!

Have u ever tried that????

I will soon

Thanks

[Lafor]

Guys, I found and dowloaded code that does allow this kind of threading with VB

at

http://www.vbaccelerator.com/codelib/thread/exethr.htm

Don't quite understand it yet!!

Please take a look and if you do understand it...
share with us...

I am currently looking at it..

Thanks

[Lafor]

Interesting...
Usually when I invoke the stored proc...
until it's completed running... My screen turns unreadable
and locked

I just tried sending this

ls_sqlString = "select count(*) from tblportTable"
Set rs_me = ExecuteInLineSql(ls_sqlString, m_objConn)

where m_objConn is an active ADO connection
rs_me is and ADODB.recordset
and ExecuteInLineSql is as follows

Public Function ExecuteInLineSql(ArgString As String, ByRef ArgConnObj As ADODB.Connection) As ADODB.Recordset

Dim m_objCmd As New ADODB.Command
Dim rs As New ADODB.Recordset

On Error GoTo ExecuteInLineSql_EH

'Set Command Object Properties
With m_objCmd
.ActiveConnection = ArgConnObj
.CommandText = ArgString
.CommandType = adCmdText

Set rs = .Execute(, , adAsyncFetchNonBlocking)
DoEvents
End With

'De-ference the Command Object
Set m_objCmd = Nothing
Set ExecuteInLineSql = rs
Set rs = Nothing
Exit Function

ExecuteInLineSql_EH:
Set ExecuteInLineSql = Nothing
End Function

Note: the option "adAsyncFetchNonBlocking" with the .execute
somehow allows me to see everything on the screen
and apparently it looks like I am not locked?

Could someone confirm or deny?

[Crazy D]

Dan Appleman has written a very intresting article about threading in VB:
http://www.desaware.com/articles/threadingL3.htm

if the link doesn't work, it's in the technical articles section, "A Thread To Visual Basic"