sql插入后获得自增主键

String sql = "insert into goods values('" + TextBox1.Text + "'," + TextBox2.Text + ",0," + TextBox3.Text + ",'','" + DropDownList1.SelectedItem.Text + "','" + Session["username"].ToString() + "',0,'" + TextBox4.Text + "','未通过');select SCOPE_IDENTITY()";
        SqlConnection conn = new SqlConnection(s);
        SqlCommand cmd = new SqlCommand(sql,conn);
        conn.Open();
        int ids= Convert.ToInt32(cmd.ExecuteScalar());