如何在mongodb中查詢數組

Question

{
 "_id":123456,
 "Menu":[{
    "Dish":"Apple pie",
    "Rating": "Good",
    "Method": "Oven Baked"
   },

   {
     "Dish":"Pumpkin Pie",
    "Rating": "Bad",
    "Method": "Baked"
   },
   {
    "Dish":"Tomato Soup",
    "Rating": "Good",
    "Method": "Boiled"
   }]

}

如果我只想在“方法”字段中顯示值，如何查詢該數組？

如何使用Pymongo解決此問題？

Answer 1

使用下面的Mongo Shell查詢

 db.mycollection.find({_id:123456}, {"Menu.Method":1})

該查詢將在您的示例文檔中產生以下結果

{
        "_id" : 123456,
        "Menu" : [
                {
                        "Method" : "Oven Baked"
                },
                {
                        "Method" : "Baked"
                },
                {
                        "Method" : "Boiled"
                }
        ]
}