Retrive A single Colon from sqlite Database

public String matchEmail(String email) { String item=null;

    SQLiteDatabase db = this.getReadableDatabase();
    String query = "SELECT email FROM Register WHERE email ='" + email+"'" ;
    Cursor  cursor = db.rawQuery(query,null);
    if (cursor.moveToFirst()) {
             while (cursor.isAfterLast() != true) {
               item=  cursor.getString(cursor.getColumnIndex("email"));
              }
    }

        //Toast.makeText(this, item, Toast.LENGTH_LONG).show();

    return item;
}

//It Dosent Return Naything