无法从数据集中提取对象值以进行比较或对其应用过滤器

Question

我正在尝试在 this page. The dataset is here

上解决问题 22

Q.22 编写一个 MongoDB 查询以查找达到“A”等级并在 ISODate“2014-08-11T00”上获得 11 分的餐厅 ID、名称和等级：许多调查日期中的 00:00Z"

数据的形式为：

[
  {
    "_key": "2451925",
    "_id": "restaurants/2451925",
    "_rev": "_buC4Kd2---",
    "address": {
      "building": "1007",
      "coord": [
        -73.856077,
        40.848447
      ],
      "street": "Morris Park Ave",
      "zipcode": "10462"
    },
    "borough": "Bronx",
    "cuisine": "Bakery",
    "grades": [
      {
        "date": {
          "$date": 1393804800000
        },
        "grade": "A",
        "score": 2
      },
      {
        "date": {
          "$date": 1378857600000
        },
        "grade": "A",
        "score": 6
      },
      {
        "date": {
          "$date": 1358985600000
        },
        "grade": "A",
        "score": 10
      },
      {
        "date": {
          "$date": 1322006400000
        },
        "grade": "A",
        "score": 9
      },
      {
        "date": {
          "$date": 1299715200000
        },
        "grade": "B",
        "score": 14
      }
    ],
    "name": "Morris Park Bake Shop",
    "restaurant_id": "30075445"
  },
  {
    "_key": "2451926",
    "_id": "restaurants/2451926",
    "_rev": "_buC4Kd2--A",
    "address": {
      "building": "469",
      "coord": [
        -73.961704,
        40.662942
      ],
      "street": "Flatbush Avenue",
      "zipcode": "11225"
    },
    "borough": "Brooklyn",
    "cuisine": "Hamburgers",
    "grades": [
      {
        "date": {
          "$date": 1419897600000
        },
        "grade": "A",
        "score": 8
      },
      {
        "date": {
          "$date": 1404172800000
        },
        "grade": "B",
        "score": 23
      },
      {
        "date": {
          "$date": 1367280000000
        },
        "grade": "A",
        "score": 12
      },
      {
        "date": {
          "$date": 1336435200000
        },
        "grade": "A",
        "score": 12
      }
    ],
    "name": "Wendy'S",
    "restaurant_id": "30112340"
  }]

我正在尝试使用上面给定的 ISODate 过滤掉日期。我正在使用 date_timestamp 函数将上述内容转换为日期在数据中的存储方式。

我无法过滤日期，因为它们似乎包含在 {"$date":1393804800000} 中。在 g 中尝试循环表明找到了一个对象而不是集合或数组。应用过滤器并检查 date_timestamp() returns 空数组 [],[] 等

是否相等

for r in restaurants
    for g in r.grades
       let d=date_timestamp("2014-08-11T00:00:00Z")
       return {date:g.date,target_date:d}

请帮忙，谢谢

Answer 1

您必须筛选对象内部的字段：

LET target_date = DATE_TIMESTAMP('2014-08-11T00:00:00Z')
FOR r IN restaurants
  FOR g IN r.grades
    FILTER g.date.$date == target_date
    RETURN {date: g.date}

无法从数据集中提取对象值以进行比较或对其应用过滤器

Unable to extract object value from dataset to compare or to apply filter on

arangodb

aql