Question

我希望能够计算每个州的经销商数量。我遇到的麻烦是我将City / State / Zip全部放在一列中。所以，我需要一种方法来从中抽象出状态。

这是我的一个结果的例子。

  "_id" : ObjectId("5a22c8e562c2e489c5df710a"),
        "2016rank" : 22,
        "Dealershipgroupname" : "West-Herr Automotive Group Inc.",
        "Address" : "3552 Southwestern Blvd.",
        "City/State/Zip" : "Orchard Park, NY 14127",
        "Phone" : "(716) 926-7052",
        "Companywebsite" : "www.westherr.com",
        "Topexecutive" : "Scott Bieler",
        "Topexecutivetitle" : "president",
        "Totalnewretailunits" : "29,486",
        "Totalusedunits" : "20,525",
        "Totalfleetunits" : 302,
        "Totalwholesaleunits" : "23,694",
        "Total_units" : "74,007",
        "Total_number_of _dealerships" : 25,
        "Grouprevenuealldepartments*" : "$1,805,200,100",
        "2015rank" : 20

这是我写的聚合组代码，但我希望它只使用State。

db.car.aggregate([
    {"$group" : {_id:"$City/State/Zip", count:{$sum:1}}}
])

那么我如何从City / State / Zip中抽出只有状态并在我的聚合中使用它呢？

Answer 1

你可以试试这个。

<html>
  <script>
    // Greetings
    var words = ['Hello', 'Hey', 'What\'s up!?'];

    function randomAlert() {

      // Index for picking the greeting you want to show
      var alertIndex;

      // Generates a number between 0 and 1
      var randomValue = Math.random();

      // 50% chance of 'Yes'
      if (randomValue < 0.5) {
        alertIndex = 0;
      }

      // 50% chance of 'No'
      else if(randomValue < 0.5) {
        alertIndex = 1;
      }



      alert(words[alertIndex])
    }
  </script>
  <button onClick="randomAlert()">Click me!</button>
</html>

从多领域专栏的Mongo抽象领域

1 个答案: