Mongo find（）不返回嵌入式文档

Question

I have a dataset with the following structure. I will show you two documents.

    {  
   "business_id":"7vqhN9Ifq5DnaUkL3jyWGg",
   "full_address":"1322 Pleasant View Rd\nMiddleton, WI 53562",
   "hours":{  },
   "open":true,
   "categories":[  
      "Active Life",
      "Golf Lessons",
      "Golf",
      "Fitness & Instruction"
   ],
   "city":"Middleton",
   "review_count":4,
   "name":"Pleasant View Golf Course",
   "neighborhoods":[  

   ],
   "longitude":-89.536493,
   "state":"WI",
   "stars":4.0,
   "latitude":43.0875811,
   "attributes":{  
      "Delivery":false,
      "Good for Kids":true,
      "Good For Groups":true,
      "Good For":{  
         "dessert":false,
         "latenight":false,
         "lunch":false,
         "dinner":false,
         "brunch":false,
         "breakfast":false
      }
   },
   "type":"business"
}

Here is another document:

    {  
   "business_id":"B0Vuwn6Hugc-0U5n31YBfg",
   "full_address":"2550 Allen Blvd\nMiddleton, WI 53562",
   "hours":{  
      "Monday":{  
         "close":"14:00",
         "open":"06:00"
      },
      "Tuesday":{  
         "close":"14:00",
         "open":"06:00"
      },
      "Friday":{  
         "close":"14:00",
         "open":"06:00"
      },
      "Wednesday":{  
         "close":"14:00",
         "open":"06:00"
      },
      "Thursday":{  
         "close":"14:00",
         "open":"06:00"
      },
      "Sunday":{  
         "close":"13:00",
         "open":"07:00"
      },
      "Saturday":{  
         "close":"14:00",
         "open":"06:00"
      }
   },
   "open":true,
   "categories":[  
      "Bakeries",
      "Food",
      "American (Traditional)",
      "Restaurants",
      "Donuts"
   ],
   "city":"Middleton",
   "review_count":25,
   "name":"C's Restaurant Bakery and Coffee Shop",
   "neighborhoods":[  

   ],
   "longitude":-89.48674,
   "state":"WI",
   "stars":4.0,
   "latitude":43.102896,
   "attributes":{  
      "Take-out":true,
      "Good For":{  
         "dessert":false,
         "latenight":false,
         "lunch":false,
         "dinner":false,
         "brunch":false,
         "breakfast":true
      },
      "Noise Level":"average",
      "Takes Reservations":false,
      "Delivery":false,
      "Ambience":{  
         "romantic":false,
         "intimate":false,
         "touristy":false,
         "hipster":false,
         "divey":false,
         "classy":false,
         "trendy":false,
         "upscale":false,
         "casual":true
      },
      "Parking":{  
         "garage":false,
         "street":false,
         "validated":false,
         "lot":true,
         "valet":false
      },
      "Has TV":false,
      "Outdoor Seating":true,
      "Attire":"casual",
      "Alcohol":"none",
      "Waiter Service":true,
      "Accepts Credit Cards":true,
      "Good for Kids":true,
      "Good For Groups":true,
      "Price Range":1
   },
   "type":"business"
}

I have aout 80000 documents in my collection. The fields in the "attribute" are not the same for each document. How will I return all the documents which have "a casual ambience". This is what I tried:

db.yelp_dataset.find({"attributes.Ambience.casual" :"true"})

However I do not get any returned data. What could be the problem?Please Help.

Answer 1

You are storing embedded document attributes.Ambience.casual field's value as Boolean and while finding the document your are passing value as string that's why no data is returning.

Try this

db.yelp_dataset.find({"attributes.Ambience.casual" :true});

instead of

db.yelp_dataset.find({"attributes.Ambience.casual" :"true"});