c# - Database Update doesn't work -

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as in title. tried everything, searched on internet everywhere doesn't work. here's code:

public void setip(string ip, string username)     {         try         {             string commandstring = "update `users` set `ip` = '@ip' 'username' = '@user';";             command = new mysqlcommand(commandstring, connection);             command.parameters.addwithvalue("@ip", ip);             command.parameters.addwithvalue("@user", username);              command.beginexecutenonquery();         }         catch (exception e)         {             messagebox.show(e.message);         }      }

i correctly put both of values strings ip , username. username textbox , ip adress doing code:

public string getip()     {         string direction = "";         webrequest request = webrequest.create("http://checkip.dyndns.org/");         using (webresponse response = request.getresponse())         using (streamreader stream = new streamreader(response.getresponsestream()))         {             direction = stream.readtoend();         }          //search ip in html         int first = direction.indexof("address: ") + 9;         int last = direction.lastindexof("</body>");         direction = direction.substring(first, last - first);          return direction;     }

and call method setip this: setip(getip(), usernamebox.text); when come database check if changed it's still same. time.

//edit: got error command: "there open datareader associated connection must closed first."

i use datareaders:

public bool findusername(string username)     {         string commandstring = "select * users username = '" + username + "';";         command = new mysqlcommand(commandstring, connection);          mysqldatareader connectionreader = command.executereader();         if (connectionreader.read())         {             connectionreader.close();             return true;         }         else         {             connectionreader.close();             return false;         }      } public bool findemail(string email)     {         string commandstring = "select * users email = '" + email + "';";         command = new mysqlcommand(commandstring, connection);          mysqldatareader connectionreader = command.executereader();          if (connectionreader.read())         {             connectionreader.close();             return true;         }         else         {             connectionreader.close();             return false;         }      } public bool loginsystem_finduser(string username, string password)     {         string commandstring = "select * users username = '"+username+"' , password = '"+password+"' ;";         command = new mysqlcommand(commandstring, connection);          mysqldatareader connectionreader = command.executereader();         if (connectionreader.read())         {             return true;         }         else         {             connectionreader.close();             return false;         }      }

i'm using "loginsystem_finduser" , after setip, finduser , findemail use registration.

'username' = '@user'

will return false because compares literally.

it's because parameters wrapped single quotes. remove single quotes , work.

string commandstring = "update `users` set `ip` = @ip username = @user;";

one more thing, column names identifiers should not surrounded single quotes.


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