Android中的sqlite查询数据时去掉重复值的方法实例

    /**     * 参数一：是否去重     * 参数二：表名     * 参数三：columns 表示查询的字段,new String[]{MODEL}表示查询该表当中的模式（也表示查询的结果）     * 参数思：selection表示查询的条件，PHONE_NUMBER+" = ?" 表示根据手机号去查询模式     * 参数五：selectionArgs 表示查询条件对应的值,new String[]{phoneNumber}表示查询条件对应的值     * 参数六：String groupBy 分组     * 参数七：String having     * 参数八：orderBy 表示根据什么排序,     * 参数九：limit 限制查询返回的行数，NULL表示无限制子句     **/    Cursor cursor = readableDatabase.query(true,TABLE_NAME, new String[]{DESCRIPTION,ID,IMAGE_URL,LATITUDE,LONGITUDE,NAME,NEED_AUDIO,SPOT_TYPE,TGROUP,AUDIO_NAME,AREA_NAME}, AREA_NAME + " = ?", new String[]{areaName}, null, null, null,null);

  /**   * 根据景区名称查询景点数据   * @param areaName   * @return 0：未查询到拦截模式（也就是该手机号没有设置拦截模式） 1：拦截短信 2：拦截电话 3：拦截所有   **/  public List<ScenicSpot> getScenicAreas(String areaName){    ArrayList<ScenicSpot> scenicSpotList = new ArrayList<>();    String model = "0";    SQLiteDatabase readableDatabase = mSmartTourSQLiteOpenHelper.getReadableDatabase();    /**     * 参数一：是否去重     * 参数二：表名     * 参数三：columns 表示查询的字段,new String[]{MODEL}表示查询该表当中的模式（也表示查询的结果）     * 参数思：selection表示查询的条件，PHONE_NUMBER+" = ?" 表示根据手机号去查询模式     * 参数五：selectionArgs 表示查询条件对应的值,new String[]{phoneNumber}表示查询条件对应的值     * 参数六：String groupBy 分组     * 参数七：String having     * 参数八：orderBy 表示根据什么排序,     * 参数九：limit 限制查询返回的行数，NULL表示无限制子句     **/    Cursor cursor = readableDatabase.query(true,TABLE_NAME, new String[]{DESCRIPTION,ID,IMAGE_URL,LATITUDE,LONGITUDE,NAME,NEED_AUDIO,SPOT_TYPE,TGROUP,AUDIO_NAME,AREA_NAME}, AREA_NAME + " = ?", new String[]{areaName}, null, null, null,null);    while (cursor.moveToNext()){      ScenicSpot scenicSpot = new ScenicSpot();      String description = cursor.getString(cursor.getColumnIndex(DESCRIPTION));      String id = cursor.getString(cursor.getColumnIndex(ID));      String image_url = cursor.getString(cursor.getColumnIndex(IMAGE_URL));      String latitude = cursor.getString(cursor.getColumnIndex(LATITUDE));      String longitude = cursor.getString(cursor.getColumnIndex(LONGITUDE));      String name = cursor.getString(cursor.getColumnIndex(NAME));      String need_audio = cursor.getString(cursor.getColumnIndex(NEED_AUDIO));      String spot_type = cursor.getString(cursor.getColumnIndex(SPOT_TYPE));      String tgroup = cursor.getString(cursor.getColumnIndex(TGROUP));      String audio_name = cursor.getString(cursor.getColumnIndex(AUDIO_NAME));      String area_name = cursor.getString(cursor.getColumnIndex(AREA_NAME));      scenicSpot.setDescription(description);      scenicSpot.setId(id);      scenicSpot.setImageurl(image_url);      scenicSpot.setLatitude(latitude);      scenicSpot.setLongitude(longitude);      scenicSpot.setName(name);      scenicSpot.setNeedAudio(need_audio);      scenicSpot.setSpotType(spot_type);      scenicSpot.setTgroup(tgroup);      scenicSpot.setAudioname(audio_name);      scenicSpot.setAreaName(area_name);      scenicSpotList.add(scenicSpot);    }    cursor.close();    readableDatabase.close();    return scenicSpotList;  }

String sql = "select distinct "   + TYPENAME   + " from "   + TABLE_NAME    + " ORDER BY " + TYPE + " ASC";  Cursor c = db.rawQuery(sql, null);

 /** * @return 所有组织结构名称 **/ public static List<String> queryTypeNames() { synchronized (DatabaseHelper.lock) {  List<String> types = null;  SQLiteDatabase db = DatabaseHelper.getInstance().getReadableDatabase();  try {  String sql = "select distinct "   + TYPENAME   + " from "   + TABLE_NAME    + " ORDER BY " + TYPE + " ASC";  Cursor c = db.rawQuery(sql, null);  while (c.moveToNext()) {   String type = c.getString(c.getColumnIndex(TYPENAME));   if (types == null) {   types = new ArrayList<String>();   }   if (type != null && type.length() > 1) {   types.add(type);   }  }  db.close();  return types;  } catch (Exception e) {  db.close();  }  return types; } }