Testing an Entity Framework database connection

I have an app that connects to a MYSQL database through the entity framework. It works 100% perfectly, but I would like to add a small piece of code that will test the connection to the database upon app startup.

I had the idea of simply running a tiny command to the database and catching any exceptions, however if there is a problem (eg App.Config missing or Database server down) the app takes a huge amount of time to run this code and then throw the exception (~1 min). I imagine this is due to connection timeouts etc but I have fiddled with such properties to no avail.

Would anyone be able to assist with any ideas as to where to go?

Are you just wanting to see if the DB connection is valid? If so take a look at the

using (DatabaseContext dbContext = new DatabaseContext())
{
     dbContext.Database.Exists();
}

http://msdn.microsoft.com/en-us/library/gg696617(v=vs.103).aspx

and for checking if a server machine is up, DB server or web services server , try this:

public PingReply Send( string hostNameOrAddress )

http://msdn.microsoft.com/en-us/library/7hzczzed.aspx

The solution as @Danilo Breda pointed out is to call the DbContext.Database.Connection.Open()

It is tested with EF6.

My implementaion:

    public static bool CheckConnection()
    {
        try
        {
            MyContext.Database.Connection.Open();
            MyContext.Database.Connection.Close();
        }
        catch(SqlException)
        {
            return false;
        }
        return true;
    }

In EntityFramework Core you can simply call: Database.CanConnect();.

(using EF Core 2.2.1)

Summary: Determines whether or not the database is available and can be connected to.

Note that being able to connect to the database does not mean that it is up-to-date with regard to schema creation, etc.

I use this code for my project:

private bool TestConnectionEF()
        {
            using (var db = new SistemaContext())
            {
                try
                {
                    db.Database.Connection.Open();
                    if (db.Database.Connection.State == ConnectionState.Open)
                    {
                        Console.WriteLine(@"INFO: ConnectionString: " + db.Database.Connection.ConnectionString 
                            + "\n DataBase: " + db.Database.Connection.Database 
                            + "\n DataSource: " + db.Database.Connection.DataSource 
                            + "\n ServerVersion: " + db.Database.Connection.ServerVersion 
                            + "\n TimeOut: " + db.Database.Connection.ConnectionTimeout);
                        db.Database.Connection.Close();
                        return true;
                    }
                    return false;
                }
                catch(Exception ex)
                {
                    throw ex;
                }
            }
        }

I know this is an old question, but here is my answer for anyone looking for a newer implementation.

I was able to use CanConnect to check the status of the database:

_database.Database.CanConnect();

# Async too
await _database.Database.CanConnectAsync(_cancellationTokenSource.Token);

I hope this helps others as well. Cheers!

I used the answer from @Sandor and did an extension method to use with EntityFramework Core.

Here's the code:

using Microsoft.EntityFrameworkCore;
using System.Data.Common;

namespace TerminalInventory
{
    public static class ExtensionMethods
    {
        public static bool TestConnection(this DbContext context)
        {
            DbConnection conn = context.Database.GetDbConnection();

            try
            {
                conn.Open();   // Check the database connection

                return true;
            }
            catch
            {
                return false;
            }
        }
    }
}

Now you just have to call:

if (!context.TestConnection())
{
    logger.LogInformation("No database connection. Check the connection string in settings.json. {0}", configuration["connectionString"]);

    return;
}

I am using the following code for MS SQL connection. Maybe, it will be useful for MySQL too. You don’t even need to use an EF or EF Core.

    public bool IsDbConnectionOK()
    {
        SqlConnectionStringBuilder conStr = new SqlConnectionStringBuilder
        {
            DataSource = ButtonServerName.Text,  // <-- My Form Elements
            InitialCatalog = ButtonDBName.Text, // <-- My Form Elements
            UserID = EditUserName.Text, // <-- My Form Elements
            Password = EditPassword.Text, // <-- My Form Elements
            IntegratedSecurity = false,
            ConnectTimeout = 30
        };

        string connectionstring = conStr.ToString();

        try
        {
            using (System.Data.SqlClient.SqlConnection connection = new System.Data.SqlClient.SqlConnection(connectionstring))
            {
                connection.Open();
                return true;
            }
        }
        catch (System.Data.SqlClient.SqlException ex)
        {
            MessageBox.Show(ex.Message + Environment.NewLine +
                "Error line: " + ex.LineNumber + Environment.NewLine +
                "Procedure name: " + ex.Procedure);
            return false;
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
            return false;
        }
    }