Mongdb操作嵌套文档

1、一个文档如下

db.posts.find()
{
    "_id" : ObjectId("5388162dfc164ee1f39be37f"),
    "title" : "Java Example",
    "content" : "This is a example for Java!",
    "comments" : []
}

 

2、往_id等于"5388162dfc164ee1f39be37f"的文档中的comments插入数据

db.posts.update({"_id":ObjectId("5388162dfc164ee1f39be37f")},{$push:{"comments":{"content":"Good Article!","author":"Luxh"}}

 再插入一条

db.posts.update({"_id":ObjectId("5388162dfc164ee1f39be37f")},{$push:{"comments":{"content":"Not bad!","author":"Chuliuxiang"}}})

 结果如下

db.posts.find()


{
    "_id" : ObjectId("5388162dfc164ee1f39be37f"),
    "title" : "Java Example",
    "content" : "This is a example for Java!",
    "comments" : [ 
        {
            "content" : "Good Article!",
            "author" : "Luxh"
        }, 
        {
            "content" : "Not bad!",
            "author" : "Chuliuxiang"
        }
    ]
}

 

3、根据内嵌文档查询

  1)查询出Luxh评论过的文章

db.posts.find({"comments.author":"Luxh"})

结果如下:
{
    "_id" : ObjectId("5388162dfc164ee1f39be37f"),
    "title" : "Java Example",
    "content" : "This is a example for Java!",
    "comments" : [ 
        {
            "content" : "Good Article!",
            "author" : "Luxh"
        }, 
        {
            "content" : "Not bad!",
            "author" : "Chuliuxiang"
        }
    ]
}

  2)查询Luxh评论过的文章,返回指定的键

db.posts.find({"comments.author":"Luxh"},{"title":1,"content":1})

结果如下:

{
    "_id" : ObjectId("5388162dfc164ee1f39be37f"),
    "title" : "Java Example",
    "content" : "This is a example for Java!"
}

  _id默认会返回。取消可设置"_id":0

 

4、修改

  将author=Luxh评论的内容content修改为"I like it!"

db.posts.update({"comments.author":"Luxh"},{$set:{"comments.$.content":"I like it!"}})

结果如下:
{
    "_id" : ObjectId("5388162dfc164ee1f39be37f"),
    "title" : "Java Example",
    "content" : "This is a example for Java!",
    "comments" : [ 
        {
            "content" : "I like it!",
            "author" : "Luxh"
        }, 
        {
            "content" : "Not bad!",
            "author" : "Chuliuxiang"
        }
    ]
}

 

5、删除

  删除comments中author=Luxh的记录

db.posts.update({},{$pull:{"comments":{"author":"Luxh"}}})

结果如下:

{
    "_id" : ObjectId("5388162dfc164ee1f39be37f"),
    "title" : "Java Example",
    "content" : "This is a example for Java!",
    "comments" : [ 
        {
            "content" : "Not bad!",
            "author" : "Chuliuxiang"
        }
    ]
}

 

 

Mongdb操作嵌套文档,古老的榕树,5-wow.com

郑重声明:本站内容如果来自互联网及其他传播媒体,其版权均属原媒体及文章作者所有。转载目的在于传递更多信息及用于网络分享,并不代表本站赞同其观点和对其真实性负责,也不构成任何其他建议。