title: An exception of type 'System.Data.SqlClient.SqlException' occurred in System.Data.dll but was not handled in user code
body: <p>I've created a local DB and a WCF Service that is supposed to insert things in a table called Vehicles, but i keep getting a Exception. The service is consumed by a website. The code for my .svc file is:</p>
  
  <pre><code>string Message;
  using (SqlConnection con = new SqlConnection("Server=localhost;Database=Vehicles;"))
  {
      con.Open();
      using (var cmd = new SqlCommand("INSERT INTO Vehicles(make,model,reg_nr,build_date,colour) values(@make,@model,@reg_nr,@build_date,@colour)", con))
      {
          cmd.Parameters.AddWithValue("@make", carInfo.Make);
          cmd.Parameters.AddWithValue("@model", carInfo.Model);
          cmd.Parameters.AddWithValue("@reg_nr", carInfo.Reg_nr);
          cmd.Parameters.AddWithValue("@build_date", carInfo.Build_date);
          cmd.Parameters.AddWithValue("@colour", carInfo.Colour);
          int result = cmd.ExecuteNonQuery();
          if (result == 1)
          {
              Message = carInfo.Make + " " + carInfo.Model + " =&gt; Success!";
          }
          else
          {
              Message = "Oops!";
          }
          con.Close();
          return Message;
      }
  }
  </code></pre>
  
  <p>I get the exception listed in the title at <code>con.Open();</code>. The <code>build_date</code> it's also nvarchar(50), because i want to make the insert work first.</p>
  
  <p>Why is it giving me this exception?</p>