nunit test case for db connection

Question

I am new to Nunit framework, C# and dotnet. How to write a test case using Nunit for a db connection. I was not able to find any examples of nunit covering db connections. The test case has to cover checking connection and closing it.

namespace TestConnection
{
    class Program
    {
        static void Main(string[] args)
        {
            Connection con = new Connection();
            con.ConnectionString = "Server = ab1-vm.app.test.com ;Port = 6080;Database = MY_DB;Schema = SCHM;User id = admin;PWD = *****;level=3;logname=C:\\my_logs";
            Command cmd = con.CreateCommand();
            Encoding e1 = Encoding.Default;
            con.Open();
            cmd.Connection = con;
            try
            {
                string query = "SELECT \"X\", \"Y\", 1 FROM MY_DB..DIM_CONTRACT Z LIMIT 50 ";
                cmd.CommandText = query;
                DataReader rdr = cmd.ExecuteReader();
                while (rdr.HasRows)
                {
                    rdr.Read();
                    System.Console.WriteLine(rdr.GetString(0));
                    System.Console.WriteLine(rdr.GetString(1));
                    System.Console.WriteLine(rdr.GetInt32(2));
                }
                rdr.Close();
                con.Close();
            }
            catch (Exception e)
            {
                System.Console.WriteLine(e.Message);
            }
        }
    }
}

Answer 1

Calling an assert function NUnit.Framework.Assert.That(con.State == ConnectionState) for con.Open() and con.close()

namespace TestProject
{
    [TestClass] //Test Framework
    public class UnitTest1
    {
        Connection con = new Connection();

        [TestMethod] //Test Case 1
        public void TestOpenConnection()
        {
            con.ConnectionString = "Server = ab1-vm.app.test.com ;Port = 6080;Database = MY_DB;Schema = SCHM;User id = admin;PWD = *****;level=3;logname=C:\\my_logs";
            con.Open();
            NUnit.Framework.Assert.That(con.State == ConnectionState.Open);
        }

    
        [TestMethod] //Test Case 2
        public void TestCloseConnection()
        {
            con.ConnectionString = "Server = ab1-vm.app.test.com ;Port = 6080;Database = MY_DB;Schema = SCHM;User id = admin;PWD = *****;level=3;logname=C:\\my_logs";
            con.Open();  //open the connection
            con.Close(); //close to test if the connection closes
            NUnit.Framework.Assert.That(con.State == ConnectionState.Closed);
        }
    }
}