if (dataSet11.Tables["book"].Rows[0]["在库数"].ToString() == "0")
                            {
                                MessageBox.Show("此书已借完!", "书讯提示");
                                textBoxBookNo.Text = "";
                                textBoxBookNo.Focus();
                                dataSet11.Clear();
                                myCommand.CommandText = "select * from borrow where" + "读者编号='" + textBoxReaderNo.Text + "'";
                                sqlDataAdapter1.SelectCommand = myCommand;
                                sqlConnection1.Open();
                                sqlDataAdapter1.Fill(dataSet11, "borrow");
                                sqlConnection1.Close();错误提示:第 1 行: '=' 附近有语法错误。
看过其他的貌似都说select语句错误,但是没看出来,谢谢大家了