oop - How to declare a dictionary compatible with any type in C# -

i have created abstract base class parent of other classes. have class database connection m fetching records , wanted records converted objects of class pass function. have written function ..

enter code here  //class appconnection.cs  public static dictionary<int, baseclass> fetchobjects( string sqlquery, baseclass obj ) {      datatable dt = myconnection.fetchrecords( sqlquery );      dictionary<int,baseclass> objdict = new dictionary<int, baseclass>();      for(int i=0; < dt.rows.count; i++ ) {         obj.mapobjectbydatarow(dt.rows[i]);      //abstract function in baseclass         objdict.add(obj.id, obj);     }      return objdict; } 

i calling in child classes this,

enter code here  class customer:baseclass  {     public static dictionary<int, customer> fetchcustomers() {         string sql = "select * customers";          dictionary<int, customer> dict = appconnection.fetchobjects(sql, new customer() );         return dict;     }  } 

this gives error cannot convert implicitly

enter code here  dictionary<int,baseclass> dictionary<int,customer> 

i think want generic method?

public static dictionary<int,t> fetchobjects<t>(string sqlquery, t obj) t : baseclass {     datatable dt = myconnection.fetchrecords( sqlquery );      dictionary<int,t> objdict = new dictionary<int, t>();      for(int i=0; < dt.rows.count; i++ ) {         obj.mapobjectbydatarow(dt.rows[i]);      //abstract function in baseclass         objdict.add(obj.id, obj);     }      return objdict; }