If there is a connection in a VFP DBC, checkout the DispWarnings property. And 
then there's the Managing Connections with SQL Pass-Through topic on the help 
file which you might find helpful.

--

rk
-----Original Message-----
From: ProfoxTech [mailto:[email protected]] On Behalf Of Kurt Wendt
Sent: Friday, July 24, 2015 10:10 AM
To: [email protected]
Subject: Connecting to SQL via VFP w/Failover...

Hello Fellow ProFoxers,

So, it recently came to my attention here at work that they have this Disaster 
Recovery location in Albany. And, the Server here in Manhattan gets Mirrored to 
a server in Albany.

For this one system - which I am now in charge of supporting - there is code to 
allow it to switch over (like the Failover in .Net) to this Albany server. But, 
when one of the systems guys recently tested the App on a Sat - by "shutting" 
down our Manhattan server - it didn't switch over to the Albany server.

More specifically - this is what happened. When the App tried to connect to the 
NYC server - it popped up a nasty error message on the screen(Connection 
failed: SQL State...). Then, if you hit OK - you get this "SQL Server Login" 
pop-up window.

The trick is - when you get to that "SQL Server Login" pop-up window - if you 
just hit Cancel - then the app will proceed to connect to the Alternate server 
in Albany. However, the systems guy - he wants to Avoid getting Error window 
and the "SQL Server Login" pop-up window. He is asking me to somehow trap for 
that situation - then handle it behind the scenes to then connect to the 
alternate server automatically.

Well - I tried doing something like that. I used the PING command - by stealing 
code from another one of our Apps - and implemented it in this App I need to 
support. So - I just pinged to see if the Server was up. I tested by F-ing up 
the Server name I was trying to connect to. So - the Ping worked - and after 
finding the failed Ping - It simply switched to connecting to the other Server.

However, the systems guy said that isn't sufficient. He told me that the Server 
could be Up - but, the Database could be down. So - I can't just Ping the 
Server and assume that would be sufficient. HE told me that a Database has Two 
States: Principal & Mirror. As such, I need to have code in place that would 
handle the situation if the Database is Down completely. Or, it must switch 
over to the Alternate server in Albany if the Database that's being connected 
to in NYC has a Status of Mirror instead of Principal.

Finally - my question to you all.

In the App it's using the SQLStringConnect command from within VFP. But, I know 
that if this command has a failure - it displays the error as previously 
mentioned - and then shows "SQL Server Login" pop-up window. I'm also assuming 
that the control of this SQLStringConnect command is outside the scope of VFP - 
and that I can't control the display of that error message. Or CAN I??? Also - 
is there any way to detect the status of the Database - of Principal vs. Mirror?

Regards,
Kurt Wendt
Consultant


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