从MongoDB中删除子文档

Question

I have the mongoDB subdocument structure like below,

{
 "basecampaign" : 
        [ 
     {     
         "timestamp" : "2014-07-28 08:09:22",  
          "latest" : 0,  
         "campaign" :
                   [ {     
                  "id" : "1",  
                  "name" : "status camp 1" 
                   } ]
    },
         {     
         "timestamp" : "2014-07-29 08:09:22",  
          "latest" : 0,  
         "campaign" :
                   [ {     
                  "id" : "2",  
                  "name" : "status camp 2" 
                   } ]
    },

         {     
         "timestamp" : "2014-07-30 08:09:22",  
          "latest" : 1,  
         "campaign" :
                   [ {     
                  "id" : "3",  
                  "name" : "status camp 3" 
                   } ]
    } 
       ]

}

I want to remove subdocument using id, I want to remove the block which has id = 3

{     
    "timestamp" : "2014-07-30 08:09:22",  
    "latest" : 1,  
    "campaign" :
           [ {     
          "id" : "3",  
          "name" : "status camp 3" 
           } ]
}

how can i acheive this any suggestion ?

Answer 1

You can use $pull. For example:

db.collection.update({},
                     {$pull:{basecampaign: {campaign.id:3}}},
                     {multi: true})

removes the basecampaign document with campaign id 3 from all documents.

Or if you want to just remove the campaign block (not clear from your question)

db.collection.update({parent document select},
                     {$pull:{basecampaign.campaign: {id:3}}})

removes the campaign block from with id 3 from all basecampaign documents in the selected partent document(s).