MongoDB探索之路(二)——系统设计之CRUD

1.构造实体类

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading.Tasks;
 6 
 7 namespace EM.Model
 8 {
 9     public class News
10     {
11         public string _id { get; set; }
12         public string title { get; set; }
13         public string url { get; set; }
14         public string author { get; set; }
15         public int vote_count { get; set; }
16         public List<string> tags { get; set; }
17         public image image { get; set; }
18         public List<comments> comments { get; set; }
19         public DateTime createTime { get; set; }
20         public DateTime updateTime { get; set; }
21     }
22     public class image 
23     {
24         public string url { get; set; }
25         public string caption { get; set; }
26         public string type { get; set; }
27         public string size { get; set; }
28         public string data { get; set; }
29     }
30     public class comments 
31     {
32         public int userId { get; set; }
33         public string user { get; set; }
34         public string text { get; set; }
35         public DateTime createTime { get; set; }
36         public DateTime updateTime { get; set; }
37     }
38 
39 
40 }

2.增加一条记录

 1             News news = new News();
 2             news._id = Guid.NewGuid().ToString();
 3             news.title = "大新闻";
 4             news.url = "http://www.cnblogs.com/cnki/";
 5             news.author = "沐风";
 6             news.vote_count = 100;
 7             List<string> tagsList = new List<string>() { "国际", "编程", "dota" };
 8             news.tags = tagsList;
 9             image img = new image();
10             img.url = "http://www.cnblogs.com/cnki/";
11             img.caption = "好图";
12             img.type = "回忆录";
13             img.size = "3M";
14             img.data = "dota三人组";
15             news.image = img;
16 
17             List<comments> commentsList = new List<EM.Model.comments>();
18             comments comment1 = new comments();
19             comment1.userId = 1;
20             comment1.user = "三生石";
21             comment1.text = "你所有的努力,只是为了更好的衬托别人的成功。";
22             comment1.createTime = DateTime.Now;
23             comment1.updateTime = DateTime.Now;
24             commentsList.Add(comment1);
25 
26             comments comment2 = new comments();
27             comment2.userId = 2;
28             comment2.user = "影魔";
29             comment2.text = "明明可以靠脸吃饭,他却偏要靠才华,最后还是饿死了。";
30             comment2.createTime = DateTime.Now;
31             comment2.updateTime = DateTime.Now;
32             commentsList.Add(comment2);
33 
34 
35             news.comments = commentsList;
36 
37             news.createTime = DateTime.Now;
38             news.updateTime = DateTime.Now;
39 
40             bool b = MongoDBServiceFactory.CreateMongoDBService(conStrNo, databaseName).Insert<News>("News", news);

存入MongoDB后的单条集合格式

{
    "_id" : "95565797-8572-4281-b6e6-6820d0c8dc37",
    "title" : "大新闻",
    "url" : "http://www.cnblogs.com/cnki/",
    "author" : "沐风",
    "vote_count" : 100,
    "tags" : [ 
        "国际", 
        "编程", 
        "dota"
    ],
    "image" : {
        "url" : "http://www.cnblogs.com/cnki/",
        "caption" : "好图",
        "type" : "回忆录",
        "size" : "3M",
        "data" : "dota三人组"
    },
    "comments" : [ 
        {
            "userId" : 1,
            "user" : "三生石",
            "text" : "你所有的努力,只是为了更好的衬托别人的成功。",
            "createTime" : ISODate("2016-12-05T13:40:46.142Z"),
            "updateTime" : ISODate("2016-12-05T13:40:46.142Z")
        }, 
        {
            "userId" : 2,
            "user" : "影魔",
            "text" : "明明可以靠脸吃饭,他却偏要靠才华,最后还是饿死了。",
            "createTime" : ISODate("2016-12-05T13:40:46.142Z"),
            "updateTime" : ISODate("2016-12-05T13:40:46.142Z")
        }
    ],
    "createTime" : ISODate("2016-12-05T13:40:46.142Z"),
    "updateTime" : ISODate("2016-12-05T13:40:46.142Z")
}

增加一条评论

1             comments commentsInfo = new comments();
2             commentsInfo.userId = 3;
3             commentsInfo.user = "mf";
4             commentsInfo.text = "世界太美好";
5             commentsInfo.createTime = DateTime.Now;
6             commentsInfo.updateTime = DateTime.Now;
7             var update = Builders<News>.Update.Push(m => m.comments, commentsInfo);
8             bool bUpdateOne = MongoDBServiceFactory.CreateMongoDBService(conStrNo, databaseName).UpdateOne<News>("News", m => m._id == "95565797-8572-4281-b6e6-6820d0c8dc37", update);

结果

 1 {
 2     "_id" : "95565797-8572-4281-b6e6-6820d0c8dc37",
 3     "title" : "大新闻",
 4     "url" : "http://www.cnblogs.com/cnki/",
 5     "author" : "沐风",
 6     "vote_count" : 100,
 7     "tags" : [ 
 8         "国际", 
 9         "编程", 
10         "dota"
11     ],
12     "image" : {
13         "url" : "http://www.cnblogs.com/cnki/",
14         "caption" : "好图",
15         "type" : "回忆录",
16         "size" : "3M",
17         "data" : "dota三人组"
18     },
19     "comments" : [ 
20         {
21             "userId" : 1,
22             "user" : "三生石",
23             "text" : "你所有的努力,只是为了更好的衬托别人的成功。",
24             "createTime" : ISODate("2016-12-05T13:40:46.142Z"),
25             "updateTime" : ISODate("2016-12-05T13:40:46.142Z")
26         }, 
27         {
28             "userId" : 2,
29             "user" : "影魔",
30             "text" : "明明可以靠脸吃饭,他却偏要靠才华,最后还是饿死了。",
31             "createTime" : ISODate("2016-12-05T13:40:46.142Z"),
32             "updateTime" : ISODate("2016-12-05T13:40:46.142Z")
33         }, 
34         {
35             "userId" : 3,
36             "user" : "mf",
37             "text" : "世界太美好",
38             "createTime" : ISODate("2016-12-05T13:44:16.831Z"),
39             "updateTime" : ISODate("2016-12-05T13:44:16.832Z")
40         }
41     ],
42     "createTime" : ISODate("2016-12-05T13:40:46.142Z"),
43     "updateTime" : ISODate("2016-12-05T13:40:46.142Z")
44 }

3.查询一条记录

 News news = MongoDBServiceFactory.CreateMongoDBService(conStr, databaseName).Single<News>("News", m => m.author == "沐风");

4.更新一条记录

a.支持数增加1

 var updateDef = Builders<News>.Update.Inc(x => x.vote_count, 1);
 bool update = MongoDBServiceFactory.CreateMongoDBService(conStr, databaseName).UpdateOne<News>("News", x => x._id == "95565797-8572-4281-b6e6-6820d0c8dc37", updateDef);

b.修改Title字段

 var update = Builders<News>.Update.Set(m => m.title, "好大的新闻");
 bool updateResult = MongoDBServiceFactory.CreateMongoDBService(conStr, databaseName).UpdateOne("News", x => x._id == "95565797-8572-4281-b6e6-6820d0c8dc37", update);

c.根据userId更新一条子评论的comments字段

 1             //找到子文档
 2             var a = Builders<News>.Filter.Eq(x => x._id, "95565797-8572-4281-b6e6-6820d0c8dc37");
 3             var b = Builders<News>.Filter.ElemMatch(x => x.comments, y => y.userId == 1);
 4             var filter = Builders<News>.Filter.And(new FilterDefinition<News>[] { a, b });
 5             //更新子文档的字段            
 6             var field = new StringFieldDefinition<News, string>("comments.$.comments");
 7             var update = Builders<News>.Update.Set(field, "修改后的我");
 8             //更新库
 9             UpdateResult updateResult = MongoDBServiceFactory.CreateMongoDBService(conStrNo, databaseName).DocumentUpdate("News", filter, update);
10             bool bupdateResult= updateResult != null && updateResult.ModifiedCount > 0 && updateResult.ModifiedCount == updateResult.MatchedCount ? true : false;

5.删除

 bool delete = MongoDBServiceFactory.CreateMongoDBService(conStr, databaseName).Delete<News>("News", x => x._id == "95565797-8572-4281-b6e6-6820d0c8dc37") > 0;

  

原文地址:https://www.cnblogs.com/cnki/p/6101597.html