android studio cant open .sqlite database file -


i'm building first app using android studio accesses external database. app crashing , giving errors saying database can not opened. i've followed videos on youtube still have problem.

when copy database .sqlite file desktop , paste assets folder error "file loaded in wrong encoding: utf-8". tried reloading file in several encodings same error message. i'm guessing issue.

any other tips or notes welcome , appreciated.

public class databasehelper extends sqliteopenhelper {     //the android's default system path of application database.     private static string db_path = "/data/data/invain3219/databases/";     private static string db_name = "partyprobedb.sqlite";     private sqlitedatabase mydatabase;     private final context mycontext;     /**      * constructor      * takes , keeps reference of passed context in order access application assets , resources.      * @param context      */     public databasehelper(context context) {         super(context, db_name, null, 1);         this.mycontext = context;     }      /**      * creates empty database on system , rewrites own database.      * */     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");             }         }     }      /**      * check if database exist avoid re-copying file each time open application.      * @return true if exists, false if doesn't      */     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 does't exist yet.         }          if(checkdb != null){             checkdb.close();         }          return checkdb != null ? true : false;     }      /**      * copies database local assets-folder created empty database in      * system folder, can accessed , handled.      * done transfering bytestream.      * */     private void copydatabase() throws ioexception{         //open local db input stream         inputstream myinput = mycontext.getassets().open(db_name);          // 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();     }      public void opendatabase() throws sqlexception {         //open database         string mypath = db_path + db_name;         mydatabase = sqlitedatabase.opendatabase(mypath, null, sqlitedatabase.open_readonly);     }      @override     public synchronized void close() {         if(mydatabase != null)             mydatabase.close();          super.close();     }      @override     public void oncreate(sqlitedatabase db) {      }      @override     public void onupgrade(sqlitedatabase db, int oldversion, int newversion) {      }      // add public helper methods access , content database.     // return cursors doing "return mydatabase.query(....)" it'd easy     // create adapters views.  }

id int change below enough , don't need " " + tableinfo.info_user + " = '" + id + "';"

 int id = curs.getint(0);      curs = db.rawquery("select * " + tableinfo.table_user_info +             " " + tableinfo.info_user + " = " + id, null);

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