1、判断订单表的的总数是否大于0,如果大于0开始上传订单
public int getOrderCount() {String query = "SELECT COUNT(*) FROM " + TABLE_NAME;Cursor cursor = db.rawQuery(query, null);int count = 0;if (cursor.moveToFirst()) {count = cursor.getInt(0);}cursor.close();return count;}
2、每一页20条数据的查询
public List query(String condition) {String sql = String.format("SELECT * FROM %s WHERE %s LIMIT %d;", TABLE_NAME, condition,20);List infoList = new ArrayList();// 执行记录查询动作,该语句返回结果集的游标//参数一:SQL查询//参数二:selectionArgs//您可以在查询的 where 子句中包含 ?s,它将被 selectionArgs 中的值替换。这些值将绑定为字符串。Cursor cursor = db.rawQuery(sql, null);//Logger.json(JSON.toJSONString(cursor));// 循环取出游标指向的每条记录while (cursor.moveToNext()) {DBOrder dbOrder = new DBOrder();dbOrder.sn = cursor.getString(cursor.getColumnIndex("sn"));dbOrder.card_no = cursor.getString(cursor.getColumnIndex("card_no"));dbOrder.total_amount = cursor.getString(cursor.getColumnIndex("total_amount"));dbOrder.rowid = cursor.getLong(cursor.getColumnIndex("id"));dbOrder.update_time = cursor.getString(cursor.getColumnIndex("update_time"));dbOrder.is_metering = cursor.getString(cursor.getColumnIndex("is_metering"));dbOrder.terminal_params = cursor.getString(cursor.getColumnIndex("terminal_params"));dbOrder.ftoken = cursor.getString(cursor.getColumnIndex("ftoken"));dbOrder.uid = cursor.getString(cursor.getColumnIndex("uid"));dbOrder.is_off = cursor.getString(cursor.getColumnIndex("is_off"));dbOrder.pay_type = cursor.getString(cursor.getColumnIndex("pay_type"));infoList.add(dbOrder);}//查询完毕,关闭数据库游标cursor.close();return infoList;}
3、获取infoList后传给后台,如果code返回200,收集ids删除掉传入的数据,在循环到第一步,直到彻底上传完为止
List ids = new ArrayList();for (DBOrder dbOrder : dbOrders){ids.add(dbOrder.rowid);}
public void delOrder(List ids) {if (ids == null || ids.isEmpty()) {return;}StringBuilder idList = new StringBuilder();for (Long id : ids) {if (idList.length() > 0) {idList.append(",");}idList.append(id);}Logger.d("删除:" + ids);// 构建删除条件,将传入的ID列表拼接成适当的条件String condition = "id IN (" + idList.toString() + ")";// 执行删除操作db.delete(TABLE_NAME, condition, null);}
分页加载数据: 如果数据库中的数据量很大,不要一次性加载所有数据到 List
中。而是分页加载,每次加载一小部分数据。这可以减轻内存负担。