Question

After a while using the website, loading contents, etc.. this message shows “Fill: SelectCommand.Connection property has not been initialized”!
I think this is because the sql connection, but not sure… I’d like to know what can i do to prevent this, every time this happens i have to upload a file (SQL class, that make the connection) and the website starts to work again.

My SQL connection:

public class SQL
{

    SqlCommand comandos;
    public SqlConnection sql()
    {
        string Server = @"server"; 
        string Username = "user"; 
        string Password = "pass"; 
        string Database = "database";
        string ConnectionString = "Data Source=" + Server + ";";
        ConnectionString += "User ID=" + Username + ";";
        ConnectionString += "Password=" + Password + ";";
        ConnectionString += "Initial Catalog=" + Database;

        SqlConnection Connection = new SqlConnection();
        try
        {
            Connection.ConnectionString = ConnectionString;
            Connection.Open();
            return Connection;
        }
        catch (Exception)
        {
            if (Connection != null)
            {
                Connection.Dispose();
        }
        return null;
        }
    }

    public void FazerComando(string comando)
    {
        comandos = new SqlCommand(comando, sql());
        comandos.ExecuteNonQuery();
    }

    public DataTable Execute(string comando)
    {
        SqlDataAdapter SQLDataAdapter = new SqlDataAdapter(comando, sql());
        DataTable dtResult = new DataTable();
        SQLDataAdapter.Fill(dtResult);
        return dtResult;
    }
}

Answer 1

This might be related to your problem, but in any case, it’s something that should be addressed: You’re not disposing your connections when you’re done with them. You should use using:

    public void FazerComando(string comando)
    {
        using (var conn = sql())
        {
            comandos = new SqlCommand(comando, conn);
            comandos.ExecuteNonQuery();
        }
    }
    public DataTable Execute(string comando)
    {
        using (var conn = sql())
        {
            SqlDataAdapter SQLDataAdapter = new SqlDataAdapter(comando, conn);
            DataTable dtResult = new DataTable();
            SQLDataAdapter.Fill(dtResult);
            return dtResult;
        }
    }