Question

我制作在线应用程序以在MS SQL中存储员工信息，我使用Disconnected模型，然后我将我的课程设为＆＃34; DataSet配置＆＃34;并在Form_Load事件中调用其中的方法。这是班级

public static string constr = ConfigurationManager.ConnectionStrings [＆＃34; cnn1＆＃34;]。ConnectionString;

public static DataSet GetDataSet(string stored_name, string table_name, params SqlParameter[] prmarr)
{
    SqlConnection con = new SqlConnection(constr);
    SqlCommand cmd = new SqlCommand(stored_name, con);
    foreach (SqlParameter prm in prmarr)
    {
        cmd.Parameters.Add(prm);
    }
    cmd.CommandType = CommandType.StoredProcedure;
    SqlDataAdapter da = new SqlDataAdapter(cmd);
    DataSet ds = new DataSet();
    da.Fill(ds, table_name);

    return ds;

我在＆＃34; Web.Config＆＃34;

中设置了连接字符串

到目前为止所有的事情都还可以，但是当我将数据插入＆＃34; DataSet＆＃34; 出现错误消息你调用的对象是空的。

这是我输入插入按钮

的代码

   int max = 0;
    foreach (DataRow dr in ds.Tables[0].Rows)
    {
        if ((int)dr["Emp_Id"] > max)
        {
            max = (int)dr["Emp_Id"];
        }
    }


    DataRow drnew = ds.Tables["x"].NewRow();
    drnew["Emp_Id"] = ++max;
    drnew["First_Name"] = txtfname.Text;
    drnew["Last_Name"] = txtlname.Text;
    drnew["Country"] = drpboxcoun.SelectedValue;
    drnew["Email"] = txtemail.Text;
    drnew["Experience_Years"] = txtexper.Text;
    drnew["Current_Salary"] = txtcursal.Text;
    drnew["Expected_Salary"] = txtexpsal.Text;

    ds.Tables["x"].Rows.Add(drnew);

问题出在哪里!!

Answer 1

我同意granadaCoder的数据类型问题
添加try catch或跟踪它...
当您要添加到此数据集时，这些“FORM feelds”会保存到DB？

这里有一些我做的代码

 public class myDAL
    {

       /// <summary>
       /// Collection of SqlParameter
       /// </summary>
       public System.Collections.Generic.List<SqlParameter> __paramList = new System.Collections.Generic.List<SqlParameter>();
    /// <summary>
    /// AddParameter -  myDAL.AddParameter(@"@_" + ParamName.ToString(), value, sqlDatatype, System.Data.ParameterDirection.Input);
    /// </summary>
    /// <param name="_paramname"></param>
    /// <param name="_paramvalue"></param>
    /// <param name="_paramtype"></param>
    /// <param name="_ParameterDirection"></param>
    /// <remarks></remarks>
    public void AddParameter(string _paramname, object _paramvalue, System.Data.SqlDbType _paramtype, ParameterDirection _ParameterDirection)
    {
        SqlParameter param = new SqlParameter(_paramname, _paramtype);
        param.Direction = _ParameterDirection;          
        param.Value = _paramvalue;
        __paramList.Add(param);
    }

    /// <summary>
    /// ParametersClear __paramList.Clear();
    /// </summary>
    public void ParametersClear()
    {
        __paramList.Clear();
    }


   public dataset Here returnDataSetSnippet(out bool hasError){

  //JUST REDO WITH DATASET


   using (SqlConnection conn = new SqlConnection(getConnection.ConnectionString()))
        {
            using (SqlCommand mySqlCommand = new System.Data.SqlClient.SqlCommand())
            {
                try
                {
                    conn.Open();
                    mySqlCommand.Connection = conn;
                    mySqlCommand.CommandType = CommandType.StoredProcedure;
                    foreach (SqlParameter p in __paramList)
                    {
                        mySqlCommand.Parameters.Add(p);

                     }

                SqlDataReader dbReader = mySqlCommand.ExecuteReader();
                    if (dbReader.Read())
                    {
                        c1 = dbReader["c1"].ToString();
                        c2 = dbReader["c2"].ToString();
                        hasError = false;
                    }

                    dbReader.Close();
                }
                catch (Exception ex)
                {
                    hasError = true;
                    //LOG HERE

                }
            } // end using
        }// end using
        return myDataSet;


             }


}

这是用法

       public myDAL = new myDAL();

      System.Data.SqlDbType sqlDatatype =   (System.Data.SqlDbType)Enum.Parse(typeof(System.Data.SqlDbType), EnumHelper.EnumDescription(Req_Param), true);

   myDAL.AddParameter(@"@_" + Req_Param.ToString(), value, sqlDatatype, System.Data.ParameterDirection.Input);

我有类型

的枚举

 public enum require_params
    {

       [Description("Int")]
       UserStatus,  
       [Description("TinyInt")]
        Mode
     }


  public static class EnumHelper
   {

    public enum Speed
    {
        [Description("5 metters per second")]
        Five = 5,
        [Description("10 metters per second")]
        Ten = 10,
        [Description("15 metters per second")]
        Fifteen = 15,
        [Description("20 metters per second")]
        Twenty = 20,
        //[Description("25 metters per second")]
        TwentyFive = 25,
       [Description("30 metters per second")]
        Thirty = 30
    }

    /// <summary>
    /// get the string value of Enum Attribute
    /// </summary>
    /// <param name="EnumConstant"></param>
    /// <returns>
    /// string enumDesctiption = EnumHelper.EnumDescription(EnumHelper.Speed.Thirty);
    ///  enumDesctiption = EnumHelper.EnumDescription(DayOfWeek.Monday); when there is no desc returns as string the ENUM property
    /// </returns>
    public static string EnumDescription(Enum EnumConstant)
    {
        System.Reflection.FieldInfo fi = EnumConstant.GetType().GetField(EnumConstant.ToString());
        DescriptionAttribute[] aattr = (DescriptionAttribute[])fi.GetCustomAttributes(typeof(DescriptionAttribute), false);
        if (aattr.Length > 0)
        {
          return aattr[0].Description;
        }
        else
        {
            return EnumConstant.ToString();
        }
    }



}

数据集在asp.net webforms中不起作用

1 个答案: