DocumentDB 获取子数组的最小值

Question

我的json数据：

[
    {
    "Code": "GB-00001",
    "BasicInformation": {
        "WGS84Longitude": -4.670000,
        "WGS84Latitude": 50.340000
     },
     "Availability": [{
            "ArrivalDate": "2017-04-21",
            "Price": 689
        },
        {
            "ArrivalDate": "2017-04-28",
            "Price": 1341
        }
     ]},
    {
    "Code": "GB-00002",
    "BasicInformation": {
        "WGS84Longitude": -4.680000,
        "WGS84Latitude": 50.350000
     },
     "Availability": [{
            "ArrivalDate": "2017-04-21",
            "Price": 659
        },
        {
            "ArrivalDate": "2017-04-28",
            "Price": 1440
        }
     ]}
}]

我希望结果如下：

[
{
    "HouseCode": "GB-00001",
    "Country": "GB",
    "location": {
        "type": "Point",
        "coordinates": [
            50.340000,
            -4.670000
        ]
    }, "lowestPrice": 689
},
{
    "HouseCode": "GB-00002",
    "Country": "GB",
    "location": {
        "type": "Point",
        "coordinates": [
            50.350000,
            -4.680000
        ]
    }, "lowestPrice" : 659
}

我的问题是：如何使用min(c.Availability.Price)

这是我当前将经纬度转换为点的查询，但不知道如何获得 minimum/lowest 价格。

SELECT c.Code, c.BasicInformation.Country , 
    {"type":"Point","coordinates": [c.BasicInformation.Latitude, c.BasicInformation.Longitude]} as location
FROM c

已经尝试使用 Join c.Availability a 和 , min(a.Price)

编辑或许我说得太早了？ https://feedback.azure.com/forums/263030-documentdb/suggestions/18561901-add-group-by-support-for-aggregate-functions 发现 url 在

Answer 1

对于用户定义的函数 (UDF)，这是非常接近理想的情况。

这是一个应该可以解决问题的方法：

function lowestPrice(availability) {
  var i, len, lowest, row;
  lowest = 2e308;
  for (i = 0, len = availability.length; i < len; i++) {
    row = availability[i];
    lowest = Math.min(lowest, row.Price);
  }
  return lowest;
};

你这样称呼它：

SELECT 
  c.Code, 
  c.BasicInformation.Country, 
  {"type":"Point","coordinates": [
    c.BasicInformation.Latitude, c.BasicInformation.Longitude
  ]} as location,
  udf.lowestPrice(c.Availability) as lowestPrice
FROM c

Answer 2

据我所知，您目前只能使用 UDF 来实现您的要求。另外，我检查了 Larry Maccherone 提供的代码，它可以在 Azure DocumentDB 服务和我的 DocumentDB 模拟器（版本 1.11.136.2）上工作，如下所示：

DocumentDB.GatewayService.exe has stopped working

对于 DocumentDB.GatewayService 崩溃，我假设您需要收集转储文件并将它们通过电子邮件附加到 askdocdb@microsoft.com。详情请参考DocumentDB Emulator troubleshooting.

DocumentDB 获取子数组的最小值

DocumentDB get min of subarray

json

nosql

azure-cosmosdb