如何解决索引超出范围的异常？ [英] how to solve index out of range Exception?

问题描述

namespace BusinessLayer
{
   public class BusinessLogic
    {
       public IEnumerable<employee> Employees
       {
           get
           {
               string cs = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;
               List<employee> employees = new List<employee>();
               using (SqlConnection con = new SqlConnection(cs))
               {
                   SqlCommand cmd = new SqlCommand("SPGETEMPLOYEE", con);
                   cmd.CommandType = CommandType.StoredProcedure;
                   con.Open();
                   SqlDataReader dr = cmd.ExecuteReader();
                   while (dr.Read())
                   {
                       Employee emp = new Employee();
                       emp.Id = Convert.ToInt32(dr["Id"]);
                       emp.name = dr["Name"].ToString();
                       emp.gender = dr["Gender"].ToString();
                       emp.mobile = dr["Mobile"].ToString();
                       emp.doj = Convert.ToDateTime(dr["doj"]);
                       employees.Add(emp);
                   }


               }


               return Employees;
           }

       }
    }
}

从数据库读取数据时获取异常。为什么任何人都可以帮助我

这里

getting the exception while reading the data from database. why can any one help me
Here

emp.Id = Convert.ToInt32(dr["Id"]);

提前感谢

thanks in advance

推荐答案

使用它：

Use this:

emp.Id = Convert.ToInt32(dr["EmpId"]);

您需要匹配列的名称使用您从DataReader访问的名称：

You need to match the names of your columns with the names you access they with from the DataReader:

select EmpId,Name,Gender,MobileNumber,Dateofjoining,[Address] from tblEmployee

列名与代码不匹配：

Does not match the column names with the code:

emp.Id = Convert.ToInt32(dr["Id"]);
emp.name = dr["Name"].ToString();
emp.gender = dr["Gender"].ToString();
emp.mobile = dr["Mobile"].ToString();
emp.doj = Convert.ToDateTime(dr["doj"]);

所以试试：

So try:

emp.Id = Convert.ToInt32(dr["EmpId"]);
emp.name = dr["Name"].ToString();
emp.gender = dr["Gender"].ToString();
emp.mobile = dr["MobileNumber"].ToString();
emp.doj = Convert.ToDateTime(dr["DateofJoining"]);

根据喜好，不要使用Convert或ToString：改为使用它：

And by preference, don't use Convert or ToString: cast it instead:

emp.Id = (int) dr["EmpId"];
emp.name = (string) dr["Name"];
emp.gender = (string) dr["Gender"];
emp.mobile = (string) dr["MobileNumber"];
emp.doj = (DateTime) dr["DateofJoining"];

使用Convert和ToString意味着您已将数据库中的值存储为字符串而不是正确的数据类型 - 这将在以后给您带来巨大的问题。

Using Convert and ToString implies that you have stored the values in your DB as strings instead of the "proper" datatypes - which would give you enormous problems later on.

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