ExecuteReader返回行，但显示为0? [英] ExecuteReader returning rows but showing count as 0?

问题描述

在这里，该过程被调用，并且该过程返回一行.这里的问题是ExecuteReader返回0行(跳过if节.我想知道它是怎么发生的

此处需要考虑的其他问题是为输出参数分配了返回值(但计数为0).请参见下面的代码.

Hi,

Here the procedure is called and the procedure is returning a row. The problem here is ExecuteReader is returning 0 rows( ,which skips the if section.I wonder how it''s happening

Other concern here is output parameter is assigned with returned value(but count is 0). See code below.

SqlConnection cn=new SqlConnection(ConfigurationManager.AppSettings["CS_localsource"]);
            
            SqlCommand cmd = new SqlCommand("validatelogin",cn);
            cmd.CommandType = CommandType.StoredProcedure;
            SqlParameter param1 =new SqlParameter("@usename",SqlDbType.VarChar,300);
            param1.Direction=ParameterDirection.Input;
            param1.Value=textBox1.Text;
            SqlParameter param2=new SqlParameter("@password",SqlDbType.VarChar,300);
            param2.Direction=ParameterDirection.Input;
            param2.Value=textBox2.Text;
            SqlParameter param3=new SqlParameter("@formname",SqlDbType.VarChar,500);
            param3.Direction=ParameterDirection.Output;
            cmd.Parameters.Add(param1);
            cmd.Parameters.Add(param2);
            cmd.Parameters.Add(param3);
            cn.Open();
            SqlDataReader dr = cmd.ExecuteReader();
        
           if (dr.Read())
           {
               MessageBox.Show("Test"+param3.Value);
           }
           else
           {
               label3.Enabled = true;
               label3.Text = "Invalid Username and Password";
               label3.BackColor = Color.Red;
                
           }
           cn.Close();
        }

非常感谢您的帮助.

Any help is greatly appreciated.

推荐答案

更改此部分

change this part

while (dr.Read())
{
  MessageBox.Show("Test"+param3.Value);
}

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