c# - How to Display data in textbox using MS Access database -

im trying display user data database textbox, user can edit/update data later.

im getting error of no value has been set @ least 1 of required parameters.

i did not write select * from, because i'm not displaying data adminrights.

can please me fix error?

this code

private void refresh_click(object sender, routedeventargs e)     {         if (!ispostback)         {             datatable dt = new datatable();             con.open();             oledbdatareader dr = null;             oledbcommand cmd = new oledbcommand("select [name], [lastname], [username], [password], [address], [email] user [id] = ?", con);             dr = cmd.executereader();             while (dr.read())             {                 name.text = (dr["name"].tostring());                 lname.text = (dr["lastname"].tostring());                 uname.text = (dr["username"].tostring());                 pass.text = (dr["password"].tostring());                 address.text = (dr["address"].tostring());                   email.text = (dr["email"].tostring());                 id.text = (dr["id"].tostring());             }             con.close();         }     } 

.....from user [id] = ?", con); 

the ? placeholder requires parameter defined in command parameters collection.

so, before calling executereader need add parameter id field

 cmd.parameters.addwithvalue("@p1", ????value id field);  dr = cmd.executereader(); 

if want retrieve single record table need know value field uniquely identifies records in table.
value necessary understand how reach code. if select row list, grid or combo, have loaded control user names , id.