在Mongo中對數組進行排序

Question

H有帶數組的json文檔。因爲我不能用push或addtoset添加到數組的開頭，所以我需要對數組進行排序。示例

{ 
    "Component": [ 
    { 
     "Id": "PDP-1", 
     "Links": {"Link": [ 
      { 
      "Text": "Western Division", 
      "Url": "/1x7-en70ai/last-minute-holidays-western-division", 
      "Title": "Last minute holidays Western Division" 
      }, 
      { 
      "Text": "Browse Regions ", 
      "Url": "/1x7-en6uly-10ts/last-minute-holidays-gambia/regions", 
      "Title": "Last minute holidays Gambia", 
      "Style": "BrowseForMore" 
      }, 
      { 
      "Text": "City of Banjul", 
      "Url": "/1x6-en6vq7/holidays-city-of-banjul", 
      "Title": "City of Banjul Holidays" 
      }, 
      { 
      "Text": "Western Division", 
      "Url": "/1x6-en70ai/holidays-western-division", 
      "Title": "Western Division Holidays" 
      } 
     ]}, 
     "Title": "Regions", 
     "Type": "PDP" 
    }, 
    { 
     "Id": "PDP-2", 
     "Links": {"Link": [ 
      { 
      "Text": "Bijilo", 
      "Url": "/1x7-enbmy6/last-minute-holidays-bijilo", 
      "Title": "Last minute holidays Bijilo" 
      }, 
      { 
      "Text": "Browse Cities ", 
      "Url": "/1x7-en6uly-10tt/last-minute-holidays-gambia/cities", 
      "Title": "Last minute holidays Gambia", 
      "Style": "BrowseForMore" 
      }, 
      { 
      "Text": "Banjul Beach", 
      "Url": "/1x6-enakgm/holidays-banjul-beach", 
      "Title": "Banjul Beach Holidays" 
      }, 
      { 
      "Text": "Bijilo", 
      "Url": "/1x6-enbmy6/holidays-bijilo", 
      "Title": "Bijilo Holidays" 
      }, 
      { 
      "Text": "Brufut Heights", 
      "Url": "/1x6-encok8/holidays-brufut-heights", 
      "Title": "Brufut Heights Holidays" 
      }, 
      { 
      "Text": "Kololi", 
      "Url": "/1x6-enpnle/holidays-kololi", 
      "Title": "Kololi Holidays" 
      }, 
      { 
      "Text": "Kotu", 
      "Url": "/1x6-enq067/holidays-kotu", 
      "Title": "Kotu Holidays" 
      } 
     ]}, 
     "Title": "Cities", 
     "Type": "PDP" 
    } 
    ], 
    "Id": "118431", 
    "Template": { 
    "PageTemplate": { 
     "Code": "2B2", 
     "text": "041 - TEMP2 - COP_CONCOU_{LAST MINUTE}" 
    }, 
    "Category": { 
     "Code": "1X7", 
     "Type": "Product", 
     "text": "Last minute holidays" 
    }, 
    "GeoObject": { 
     "Code": "EN6ULY", 
     "text": "Gambia, The" 
    }, 
    "GeoObjectType": { 
     "Code": "1A", 
     "text": "Political" 
    }, 
    "GeoObjectSubType": { 
     "Code": "10TR", 
     "text": "Country" 
    } 
    }, 
    "Type": "Content", 
    "Url": "/1x7-en6uly/last-minute-holidays-gambia", 
    "_id": {"$oid": "528492d4c90fa9fcd0436929"} 
} 

我想在Links.Link'BrowseForMore'中按Style排序。任何想法如何做到這一點？我想我可以通過push添加虛擬數組，然後按照我想要的方式進行分類。任何幫助表示讚賞

Answer 1

您似乎想要更新數組並保持排序順序與列表前面的Links.Link.Style值。在這種情況下，使用帶更新的$sort修飾符。

db.collection.update(
    { _id: id }, 
    { $push: { "Links.Link: {$each: [doc], $sort { Style: -1 }}} } 
) 

的$each要求操作員即使只有一個文件，但可以採取很多。

如果您嘗試使用$addToSet來維護唯一的文檔，官方的MongoDB行是集被認爲是無序的，因此修飾符在這裏不可用。