Question

我在查找代码出现问题时遇到了一些麻烦调试器命中执行查询时抛出第一次机会异常，我知道这不是查询，因为我在SQL Management Studio中测试了它。如果有人能给我一些有关错误的见解，我们将不胜感激。

这是我的代码，

/// <summary>
    /// 
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    protected void Page_Load(object sender, EventArgs e) {
        if (!IsPostBack) {
            string con_string = WebConfigurationManager.ConnectionStrings["CHDBConnectionString"].ConnectionString;
            SqlConnection con = new SqlConnection(con_string);
            SqlCommand cmd = new SqlCommand("SELECT SUBSTRING(NursingUnitID, 1, 1) AS Floor, COUNT(*) AS Patients" +
                                            "FROM Admissions" +
                                            "WHERE SUBSTRING(NursingUnitID, 1, 1) IN ('1', '2', '3')" +
                                            "AND DischargeDate IS NULL" +
                                            "GROUP BY SUBSTRING(NursingUnitID, 1, 1)", con);

            try {
                using (con) {
                    con.Open();
                    SqlDataReader reader = cmd.ExecuteReader();

                    chtFloor.Series["Series1"].Name = "currentPatients";
                    chtFloor.Series["currentPatients"].Points.DataBindXY(reader, "Floor", "Patients");

                    chtFloor.Width = 600;
                    chtFloor.Height = 600;
                    chtFloor.BorderSkin.SkinStyle = BorderSkinStyle.Emboss;
                    chtFloor.Titles.Add(new Title("Number of Current Patients on Each Floor", Docking.Top, new Font("Arial", 20f), Color.Black));
                    chtFloor.Titles.Add(new Title("Nursing Unit", Docking.Bottom, new Font("Arial", 12f), Color.Black));
                    chtFloor.BackColor = System.Drawing.ColorTranslator.FromHtml("AliceBlue");
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }
        }
    }

Answer 1

连接字符串时应添加空格：

SqlCommand cmd = new SqlCommand(
    "SELECT SUBSTRING(NursingUnitID, 1, 1) AS Floor, COUNT(*) AS Patients " +
    "FROM Admissions " +
    "WHERE SUBSTRING(NursingUnitID, 1, 1) IN ('1', '2', '3') " +
    "AND DischargeDate IS NULL " +
    "GROUP BY SUBSTRING(NursingUnitID, 1, 1)", con);

第一次机会异常ASP.NET

1 个答案: