C# 引用驱动程序 MongoDB.Driver

建立连接

 private static  MongoClient client = new MongoClient("mongodb://127.0.0.1:27017");
        //获取指定数据库
 private static IMongoDatabase db = client.GetDatabase("DPdate");

Mongodb有一个特性，你可以不用先建数据库和集合，数据库会自行检查，如果没有就新建。

IMongoCollection<> collection = dbBase.GetCollection<>("Class"); //获取集合

也可以自动序列化 自己建model实体

IMongoCollection collection = dbBase.GetCollection("Class");

Linq 语法 查询

var schoolClass = collection.Find(n => n.ClassName == "一年级").FirstOrDefault();
var schoolClass2 = collection.AsQueryable().Where(n => n.ClassName == "一年级").FirstOrDefault();
var schoolClass3 = collection.Find(new BsonDocument("ClassName", "一年级")).FirstOrDefault();

Mongodb驱动程序还支持异步方法，根据命名约定，很多方法相应的Async结尾的，都是异步方法。

var schoolClass = await collection.Find(n => n.ClassName == "一年级").FirstOrDefaultAsync();
var schoolClass2 = await  collection.AsQueryable().Where(n => n.ClassName == "一年级").FirstOrDefaultAsync();
var schoolClass3 = await  collection.Find(new BsonDocument("ClassName", "一年级")).FirstOrDefaultAsync();

增加-

IMongoCollection collection = dbBase.GetCollection("Class");
//写入单个
collection.InsertOne(new Class
{ClassName = "二年级",StudentItems = new List{new Student{Age=10,Name="李明",Sex="男" },new Student{Age=12,Name="小红",Sex="女" }}
});
//批量写入
collection.InsertMany(new List
{new Class{ClassName = "二年级",StudentItems = new List{new Student{Age=10,Name="李明",Sex="男" },new Student{Age=12,Name="小红",Sex="女" }}}
});

IMongoCollection collection = dbBase.GetCollection("Class");
//写入单个
collection.InsertOne(new BsonDocument {{"ClassName","二年级" },{"StudentItems",new BsonArray{new BsonDocument { { "Age", 10 },{ "Name", "李明" },{ "Sex", "男" } }}}
});
//批量写入
collection.InsertMany(new List
{new BsonDocument {{"ClassName","二年级" },{"StudentItems",new BsonArray{new BsonDocument { { "Age", 10 },{ "Name", "李明" },{ "Sex", "男" } }}} },new BsonDocument {{"ClassName","二年级" },{"StudentItems",new BsonArray{new BsonDocument { { "Age", 10 },{ "Name", "李明" },{ "Sex", "男" } }}} }
});

使用C#语言习惯自己建 实体类

-删除

IMongoCollection collection = dbBase.GetCollection("Class");
//删除单个
collection.DeleteOne(n => n.ClassName == "二年级");//使用拉姆达表达式
collection.DeleteOne(new BsonDocument("ClassName", "二年级"));//使用BsonDocument
var filter = Builders.Filter.Eq("_id", new BsonObjectId("5a545e9381a98c3ab46c9cb9"));
collection.DeleteOne(filter);//使用Builders，
//批量删除
collection.DeleteMany(n => n.ClassName == "二年级");
collection.DeleteMany(new BsonDocument("ClassName", "二年级"));
collection.DeleteMany(filter);
//删除并返回
collection.FindOneAndDelete(n => n.ClassName == "三年级");

IMongoCollection collection = dbBase.GetCollection("Class");
//删除单个
collection.DeleteOne(new BsonDocument("ClassName", "二年级"));//使用BsonDocument
var filter = Builders.Filter.Eq("_id", new BsonObjectId("5a545e9381a98c3ab46c9cb9"));
collection.DeleteOne(filter);//使用Builders，
//批量删除
collection.DeleteMany(new BsonDocument("ClassName", "二年级"));
collection.DeleteMany(filter);
//删除并返回
collection.FindOneAndDelete(new BsonDocument("ClassName", "二年级"));

使用BsonDocument，就不能使用酷酷的拉姆达表达式了，其它的差不多。

---------------------------更改---------------------------------

IMongoCollection collection = dbBase.GetCollection("Class");
//修改单个
var filter = Builders.Filter.Eq("_id", new BsonObjectId("5a545e9381a98c3ab46c9cb8"));
var update = Builders.Update.Set("ClassName", "三年级");
var update2 = Builders.Update.Set(n => n.ClassName, "三年级");collection.UpdateOne(n => n.ClassName == "二年级", update);//使用拉姆达表达式
collection.UpdateOne(filter, update2);//使用Builders
//批量修改
collection.UpdateMany(n => n.ClassName == "二年级", update);
collection.UpdateMany(filter, update2);
//替换
var schoolClass = collection.Find(n => n.ClassName == "二年级").FirstOrDefault();
collection.ReplaceOne(n => n.ClassName == "二年级", schoolClass);

使用BsonDocument 也是相应差不多，我就不贴出代码了,修改数组，则大概如下

//数组增加一个
var update = Builders.Update.Push("StudentItems", new Student { Age = 18, Name = "张明", Sex = "男" });
collection.UpdateOne(n => n.ClassName == "三年级", update);
//数组减少一个
var update2 = Builders.Update.Pull(n => n.StudentItems, new Student { Age = 18, Name = "张明", Sex = "男" });
collection.UpdateOne(n => n.ClassName == "三年级", update2);
//数组修改一个
var update3 = Builders.Update.Set("StudentItems.$.Age", 30);
collection.UpdateOne(n => n.ClassName == "三年级" && n.StudentItems.Any(m=>m.Age==10), update3);
var update4 = Builders.Update.Set("StudentItems.$", new Student { Age = 18, Name = "张明", Sex = "男" });
collection.UpdateOne(n => n.ClassName == "三年级" && n.StudentItems.Any(m => m.Age == 10)

 本文参考：奇怪的知识在增长