Question

I have a C# Console Application that is essentially a long batch process that processes data on a nightly basis across many different databases. What is the proper or preferred way to test basic database connectivity at the beginning of this type of program? I ran into the issue of having an expired database password for one of my connections that was caught by exception handling but I want to test for basic connectivity at the very beginning.

Would a simple SELECT query suffice or is there a more efficient way of doing this for numerous databases?

Answer 1

IMHO the simplest way is trying to connect to database and, if you have a failure, you give up.
As you’re running a night batch, it’s not important to understand immediately the reason and solve it.
So something like this

using(SqlConnection conn = new SqlConnection(connectionString))
{
    try
    {
        conn.Open();
        // Do what you please here        
    }
    catch (Exception ex)
    {
        // Write error to file
        File.Append(..., 
            DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss") + " " + 
            ex.Message);
    }
    finally 
    { 
        conn.Close();
    } 
}

Next morning you can check file for errors…