我有一个json对象,如下所示:
{ "_id" : ObjectId("508806803bb97dc546e6f307"), "user_name" : "user1", "user_id" : 45645645, "likes" : [ { "event_id" : NumberLong("4578541212") },{ "event_id" : NumberLong("4578541213") } ], "dislikes" : [ ] }
我正在尝试通过Java驱动程序在Likes数组中删除特定事件
尝试首先在shell中执行此操作:
> db.users.update( {'likes.event_id' : 4578541212}, { '$unset':{'likes.event_id'
:1}})
没运气...我该怎么办呢?
最佳答案
如果只想从数组元素中删除event_id
字段:
db.users.update( {'likes.event_id' : 4578541212}, {'$unset':{'likes.$.event_id' :1}})
使用
$pull
运算符删除元素:db.users.update({'likes.event_id': 4578541212}, {'$pull':{likes: {event_id: 4578541212}}})