java - Not able to copy the existing Database in Android -

i new android development,so have existing database called courses,and databasehelper file copy existing file assets folder in android studio runs loop , creates empty database android_manifest file in ,"no tables copied".so therefore giving me , error of no table found when running select table.

error: e/androidruntime: fatal exception: main process: com.example.sinhanikita17.myapplication, pid: 15127 java.lang.runtimeexception: unable start activity componentinfo{com.example.sinhanikita17.myapplication/com.example.sinhanikita17.myapplication.choose}: android.database.sqlite.sqliteexception: no such table: ics (code 1): ,

public class databasehelper extends sqliteopenhelper { private static string db_path;

private static string db_name = "courses.db";  private sqlitedatabase mydatabase;  private final context mycontext;  private static final string logtag = "myapp5"; private static databasehelper _dbhelper;  public databasehelper(context context) {      super(context, db_name, null, 1);     this.mycontext = context;           db_path =  "/data/data/" + context.getpackagename() + "/databases/";     log.i(logtag, db_path); }  public static databasehelper getinstance(context context) {     if(_dbhelper == null)     {         _dbhelper = new databasehelper(context);     }     return _dbhelper; }  public void createdatabase() throws ioexception{       boolean dbexist = checkdatabase();      if(dbexist){         //do nothing - database exist     }else{          //by calling method , empty database created default system path         //of application gonna able overwrite database our database.          this.getreadabledatabase();           try {             copydatabase();          } catch (ioexception e) {              throw new error("error copying database");         }     } }  private boolean checkdatabase(){      sqlitedatabase checkdb = null;      try{         string mypath = db_path + db_name;         checkdb = sqlitedatabase.opendatabase(mypath, null, sqlitedatabase.open_readonly);      }catch(sqliteexception e){          //database doesn't exist yet.      }      if(checkdb != null) checkdb.close();      return checkdb != null ? true : false; }  private void copydatabase() throws ioexception{      //open local db input stream     inputstream myinput = mycontext.getassets().open("courses.db");     log.i(logtag, string.valueof(mycontext.getassets()));      // path created empty db     string outfilename = db_path + db_name;      //open empty db output stream     outputstream myoutput = new fileoutputstream(outfilename);      //transfer bytes inputfile outputfile     byte[] buffer = new byte[1024];     int length;     while ((length = myinput.read(buffer)) > 0){             myoutput.write(buffer, 0, length);     }      //close streams     myoutput.flush();     myoutput.close();     myinput.close();  }