Connection property has not been initialized c# -

im getting when execute non query .. calling executenonquery....

   clsconnection.executenonquery("add_customers", commandtype.storedprocedure, paramlist); 

exception pop @ cmd.connection.open();

this whole executenonquery

 public static void executenonquery(string sql, commandtype type, list<sqlparameter> paramlist)             try         {             dataaccess.clsconnection clsdb = new dataaccess.clsconnection();             using (sqlconnection cn =clsdb.opencon())             {                 sqlcommand cmd = new sqlcommand();                 cmd = createcommand(sql, type, paramlist);                 cmd.connection = cn;                 cmd.commandtype = type;                 cmd.commandtext = sql;                 cmd.executenonquery();               }   

you don't assign connection object command

when sqlcommand executes query needs open connection. first step search connection property see if has been initialized. property null , error

simply fix with

 cmd.connection = maincon; 

of course, have opened connection , don't need line

 cmd.connection.open(); 

said that, suggest avoid keep global connection object in way. better performance , impact on system resources used program change opencon return connection opened , use using statement free resource when no more needed

namespace dataaccess {     public class clsconnection     {         public sqlconnection opencon()         {                            dbn = "pms";                 server = "server-pc\\sqlexpress";                 user = "sa";                 pwd = "sysadmin123";                  sqlconnection cn = new sqlconnection("initial catalog=" + dbn + ";data source=" + server + "; user id =" + user + "; password =" + pwd + ";connect timeout=10");                 .....                 cn.open();                                    return cn;          }              } } 

so code use connection changed to

try {    dataaccess.clsconnection clsdb = new dataaccess.clsconnection();    using(sqlconnection cn = clsdb.opencon())    {        sqlcommand cmd = new sqlcommand();        cmd = createcommand(sql, type, paramlist);        cmd.connection = cn;        cmd.commandtype = type;        cmd.commandtext = sql;        cmd.executenonquery();      // here closing braces closes , disposes connection freeing resources used     // in case of exceptions      }   } catch (exception ex) {     .... } 

edit: seeing comment below, added more context method opencon. suggest change code , take advantage of using statement