如何在更新查询中添加或包含数组？

1 回答

• 3

  是的，这是可行的 . 我试过这样的：
  （在mongo shell上运行;客户端和服务器都是V2.6.4）

  function tryAndFine(coll, key, value) {
      var entry = {};
      entry[key] = value;
  
      var parent = 'data';
      var prefix = parent + '.';
  
      function incrementOnly() {
          var criteria = {};
          criteria[prefix + key] = {$exists : true};
  
          var update = {};
          update[prefix + "$." + key] = value;
  
          var result = coll.update(criteria, {$inc : update});
          // if increment fails, try to add a new one
          if (result.nModified == 0) {
              addNewElement();
          }
      }
  
      function addNewElement() {
          var criteria = {};
          criteria[prefix + key] = {$exists : false};
  
          var update = {};
          update[parent] = entry;
  
          var result = coll.update(criteria, {$push : update}, {upsert : true});
          // if exists, try to increment the count
          if (result.upserted == 0 && result.nModified == 0) {
              incrementOnly();
          }
      }
  
      // run entry
      incrementOnly();
  }
  
  // test
  var c = db.c;
  c.drop();
  tryAndFine(c, '20141103', 1);
  tryAndFine(c, '20141103', 1);
  tryAndFine(c, '20141104', 1);
  tryAndFine(c, '20141105', 1);
  tryAndFine(c, '20141104', 1);
  
  // output
  {
      "_id" : ObjectId("54577e1a3502852bd4ad2395"),
      "data" : [ {
          "20141103" : 2
      }, {
          "20141104" : 2
      }, {
          "20141105" : 1
      } ]
  }
  

  回复于 2024-05-02T06:30:54+08:00