SqlConnection conn = new SqlConnection("Data Source=localhost;Initial Catalog=Book1;Integrated Security=true;");
            conn.Open();

            string sql = "select bookTypeID from BookType where bookType="+comboBox1.SelectedItem;//此处有错
            SqlCommand comm1 = new SqlCommand(sql, conn);
            SqlDataReader read1 = comm1.ExecuteReader(CommandBehavior.CloseConnection);
            read1.Read();
            textBox1.Text = read1["bookTypeID"].ToString() ;
          报错，列名找不到