sql - ASP.Net C# failed to UPDATE picture but success when INSERT new picture to Database -

i using .ashx file imagehandler.

the error message received exception of type 'system.invalidoperationexception' occurred in system.data.dll not handled in user code

additional information: invalid attempt read when no data present.

this part showing error      sqldatareader dr = cmd.executereader();        dr.read();        context.response.contenttype = dr["image_type"].tostring();        context.response.binarywrite((byte[])dr["profile_picture"]);        dr.close(); 

this imagehandler.ashx:

using system; using system.collections.generic; using system.linq; using system.web; using system.web.ui; using system.web.ui.webcontrols;  using system.data.sqlclient; using system.data; using system.configuration; using system.io;  public class imagehandler : ihttphandler {    public void processrequest (httpcontext context) {   sqlconnection myconnection = new sqlconnection(configurationmanager.connectionstrings["register"].connectionstring);   myconnection.open();    string sql = "select profile_picture, image_type member login_id=@name";    sqlcommand cmd = new sqlcommand(sql, myconnection);   cmd.parameters.add("@name", sqldbtype.nvarchar).value = context.request.querystring["login_id"];     sqldatareader dr = cmd.executereader();    dr.read();    context.response.contenttype = dr["image_type"].tostring();    context.response.binarywrite((byte[])dr["profile_picture"]);    dr.close();   myconnection.close();      }      public bool isreusable {         {             return false;         }     }  } 

this updateprofile.aspx.cs:

    protected void btnsave_click(object sender, eventargs e)     { string constr = configurationmanager.connectionstrings["register"].connectionstring;         string filename = path.getfilename(fuprofilepicture.postedfile.filename);         string contenttype = fuprofilepicture.postedfile.contenttype;          using (stream fs = fuprofilepicture.postedfile.inputstream)         {             using (binaryreader br = new binaryreader(fs))             {                 byte[] bytes = br.readbytes((int32)fs.length);                  using (sqlconnection con1 = new sqlconnection(constr))                 {                     string query1 = "update member set name = @name,                           email = @email, phone_number = @phonenumber,                           gender = gender, date_of_birth = @dob,                           password = @password, login_id = @loginid,                          student_id = @studentid,                           profile_picture = @profilepicture                           login_id = '" + request.querystring["login_id"] + "'";                     using (sqlcommand cmd1 = new sqlcommand(query1))                     {                          cmd1.connection = con1;                         cmd1.parameters.addwithvalue("@imagename", filename);                         cmd1.parameters.addwithvalue("@imagetype", contenttype);                         cmd1.parameters.addwithvalue("@profilepicture", bytes);                         cmd1.parameters.addwithvalue("@name", txtname.text);                         cmd1.parameters.addwithvalue("@email", txtemail.text);                         cmd1.parameters.addwithvalue("@phonenumber", txtcontactnumber.text);                         cmd1.parameters.addwithvalue("@gender", ddlgender.selecteditem.tostring());                         cmd1.parameters.addwithvalue("@dob", ddlday.selecteditem.tostring() + "/" + ddlmonth.selecteditem.tostring() + "/" + txtyear.text);                         cmd1.parameters.addwithvalue("@password", txtpassword.text);                         cmd1.parameters.addwithvalue("@loginid", txtusername.text);                         cmd1.parameters.addwithvalue("@studentid", txtstudentid.text);                         con1.open();                         cmd1.executenonquery();                         con1.close();                     }                 }             }         }         system.text.stringbuilder sb = new system.text.stringbuilder();         sb.append("<script type = 'text/javascript'>");         sb.append("window.onload=function(){");         sb.append("alert('");         sb.append("update successfuly!");         sb.append("')};");         sb.append("</script>");         clientscript.registerclientscriptblock(this.gettype(), "alert", sb.tostring());     }           } 

maybe because forget @ sign on gender:

phone_number = @phonenumber, gender = gender,