$pull mongodb 不会删除项目

huangapple
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英文:

$pull mongodb is not removing items

问题

我有一个集合：

  1. //the json.
  2. {
  3.     "ItemsToDelete" : [ 
  4.         {
  5.             "placeId" : "ChIJIQBpAG2ahYAR_6128GcTUEo",
  6.             "users" : [ 
  7.                 ObjectId("547e4650f3fb0a022110af15"), 
  8.                 ObjectId("547e4650f3fb0a022110af15"), 
  9.                 ObjectId("547e4650f3fb0a022110af15")
  10.             ]
  11.         }, 
  12.         {
  13.             "placeId" : "ChIJIQBpAG2ahYAR_6128GcTUEo",
  14.             "users" : [ 
  15.                 ObjectId("547e4650f3fb0a022110af15"), 
  16.                 ObjectId("547e4650f3fb0a022110af15"), 
  17.                 ObjectId("547e4650f3fb0a022110af15")
  18.             ]
  19.         }, 
  20.         {
  21.             "placeId" : "ChIJIQBpAG2ahYAR_6128GcTUEo",
  22.             "users" : [ 
  23.                 ObjectId("547e4650f3fb0a022110af15"), 
  24.                 ObjectId("547e4650f3fb0a022110af15"), 
  25.                 ObjectId("547e4650f3fb0a022110af15")
  26.             ]
  27.         }
  28.     ]
  29. }  
  31. {
  32.     "ItemsToRemove" : [ 
  33.         {
  34.             "ChIJIQBpAG2ahYAR_6128GcTUEo" : [ 
  35.                 ObjectId("547e4650f3fb0a022110af15"), 
  36.                 ObjectId("547e4650f3fb0a022110af15"), 
  37.                 ObjectId("547e4650f3fb0a022110af15")
  38.             ]
  39.         }, 
  40.         {
  41.             "ChIJIQBpAG2ahYAR_6128GcTUEo" : [ 
  42.                 ObjectId("547e4650f3fb0a022110af15"), 
  43.                 ObjectId("547e4650f3fb0a022110af15"), 
  44.                 ObjectId("547e4650f3fb0a022110af15")
  45.             ]
  46.         }, 
  47.         {
  48.             "ChIJIQBpAG2ahYAR_6128GcTUEo" : [ 
  49.                 ObjectId("547e4650f3fb0a022110af15"), 
  50.                 ObjectId("547e4650f3fb0a022110af15"), 
  51.                 ObjectId("547e4650f3fb0a022110af15")
  52.             ]
  53.         }
  54.     ]
  55. }

然后我运行这个mongo shell查询来删除数组中的一个项目：

  1. db.users.update(
  2.     {"_id":ObjectId("54e664c4e7c3b4d3b5413e39")},
  3.     {$pull:{ItemsToDelete : {placeId:"ChIJIQBpAG2ahYAR_6128GcTUE"}}},
  4.     {multi: true}
  5. )

数组仍然没有被修改。有什么想法为什么无法成功使用$pull？

我尝试过使用'ItemsToDelete.placeId'，但是会出现错误：当执行"ItemsToDelete.placeId"时收到的错误消息为'cannot use the part (ItemsToDelete of ItemsToDelete.placeId) to traverse the element'。

英文:

I have a collection:

  1. //the json.
  2. {
  3. "ItemsToDelete" : [ 
  4.         {
  5.             "placeId" : "ChIJIQBpAG2ahYAR_6128GcTUEo",
  6.             "users" : [ 
  7.                 ObjectId("547e4650f3fb0a022110af15"), 
  8.                 ObjectId("547e4650f3fb0a022110af15"), 
  9.                 ObjectId("547e4650f3fb0a022110af15")
  10.             ]
  11.         }, 
  12.         {
  13.             "placeId" : "ChIJIQBpAG2ahYAR_6128GcTUEo",
  14.             "users" : [ 
  15.                 ObjectId("547e4650f3fb0a022110af15"), 
  16.                 ObjectId("547e4650f3fb0a022110af15"), 
  17.                 ObjectId("547e4650f3fb0a022110af15")
  18.             ]
  19.         }, 
  20.         {
  21.             "placeId" : "ChIJIQBpAG2ahYAR_6128GcTUEo",
  22.             "users" : [ 
  23.                 ObjectId("547e4650f3fb0a022110af15"), 
  24.                 ObjectId("547e4650f3fb0a022110af15"), 
  25.                 ObjectId("547e4650f3fb0a022110af15")
  26.             ]
  27.         }
  28.     ]
  29. }  
  32. {
  33. "ItemsToRemove" : [ 
  34.         {
  35.             "ChIJIQBpAG2ahYAR_6128GcTUEo" : [ 
  36.                 ObjectId("547e4650f3fb0a022110af15"), 
  37.                 ObjectId("547e4650f3fb0a022110af15"), 
  38.                 ObjectId("547e4650f3fb0a022110af15")
  39.             ]
  40.         }, 
  41.         {
  42.             "ChIJIQBpAG2ahYAR_6128GcTUEo" : [ 
  43.                 ObjectId("547e4650f3fb0a022110af15"), 
  44.                 ObjectId("547e4650f3fb0a022110af15"), 
  45.                 ObjectId("547e4650f3fb0a022110af15")
  46.             ]
  47.         }, 
  48.         {
  49.             "ChIJIQBpAG2ahYAR_6128GcTUEo" : [ 
  50.                 ObjectId("547e4650f3fb0a022110af15"), 
  51.                 ObjectId("547e4650f3fb0a022110af15"), 
  52.                 ObjectId("547e4650f3fb0a022110af15")
  53.             ]
  54.         }
  55.     ]
  56. }

I then run this mongo shell query to pull an item off the array and delete:

  1. db.users.update({"_id":ObjectId("54e664c4e7c3b4d3b5413e39")},{$pull:{ItemsToDelete : {placeId:"ChIJIQBpAG2ahYAR_6128GcTUE"}}},{ multi: true })

The array remains unmodified. Any thoughts why this is failing to $pull?

I have tried 'ItemsToDelete.placeId' but that errors out with: error I receive when doing “ItemsToDelete.placeId” => ‘cannot use the part (ItemsToDelete of ItemsToDelete.placeId) to traverse the element’

答案1

得分: 2

你的查询没有返回任何项，因为在placeId的值中缺少了o。

应该是这样的：

  1. > db.users.update(
  2.     {"_id":ObjectId("54e664c4e7c3b4d3b5413e39")},
  3.     {$pull:{ItemsToDelete : {placeId:"ChIJIQBpAG2ahYAR_6128GcTUEo"}}},
  4.     { multi: true }
  5.   )
  7. WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
  9. > db.users.find().pretty()
  10. { "_id" : ObjectId("54eac8d51a0c74438c9dea10"), "ItemsToDelete" : [ ] }
英文:

You query doesn't pull any item because you are missing o in placeId value.

  1. > db.users.update(
  2.     {"_id":ObjectId("54e664c4e7c3b4d3b5413e39")},
  3.     {$pull:{ItemsToDelete : {placeId:"ChIJIQBpAG2ahYAR_6128GcTUE"}}},
  4.                                                                 ^
  5.     { multi: true }
  6.   )

Should be

  1. > db.users.update(
  2.     {"_id":ObjectId("54e664c4e7c3b4d3b5413e39")},
  3.     {$pull:{ItemsToDelete : {placeId:"ChIJIQBpAG2ahYAR_6128GcTUEo"}}},
  4.     { multi: true }
  5.   )
  7. WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
  9. > db.users.find().pretty()
  10. { "_id" : ObjectId("54eac8d51a0c74438c9dea10"), "ItemsToDelete" : [ ] }

huangapple
  • 本文由 发表于 2015年2月23日 05:09:11
  • 转载请务必保留本文链接：https://go.coder-hub.com/28663273.html
  • arrays
  • go
  • javascript
  • mongodb
  • pull
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