.NET中好用的MongoDb ORM很少，选择也很少，所以我打造了一款适合SQL习惯的MongoDb ORM，让用户多一个选择。

1、 MongoDB ORM教程

1.1 NUGET 安装

SqlSugar.MongoDbCore
SqlSugarCore

1.2 已支持功能

单表CRUD+分页+排序+简单分组+嵌套文件（类似Json类型）+简单联表

1.3 创建DB对象

//注册DLL防止找不到DLL（扔在程序启动时）
 InstanceFactory.CustomAssemblies = new System.Reflection.Assembly[] {
 typeof(SqlSugar.MongoDb.MongoDbProvider).Assembly };
  
 //db对象（用法和sqlsugar入门中一样）
  var db = new SqlSugarClient(new ConnectionConfig()
  {
      IsAutoCloseConnection = true,
      DbType = DbType.MongoDb,
      ConnectionString = SqlSugarConnectionString 
 
  },
  it =>
  { 
      it.Aop.OnLogExecuting = (sql, para) =>
      {   //AOP打印SQL
          Console.WriteLine(UtilMethods.GetNativeSql(sql, para));
      };
  });
   
   
 //字符串2种都可以
var ConnectionString = "mongodb://root:123456@222.71.212.3:27017/testDB?authSource=admin";
var  ConnectionString  = "host=222.71.212.3;Port=27017;Database=testDB;Username= root;Password=123456;authSource=admin;replicaSet=";

 

1.4 实体类定义（重点注意）

主键定义：继承MongoDbBase里面自定义好了主键

外键定义 ：设置 ColumnDataType =nameof(ObjectId)

 //继承的MongoDbBase里面已经有了主键，当然你也可以复制出来不用基类
   public class Student:MongoDbBase
   {
       //主键在基类，也可以自个复制出来不用基类
       public string Name { get; set; }
        
       //外键需要设置ObjectId类型不然存储会的是string
       [SqlSugar.SugarColumn(ColumnDataType =nameof(ObjectId))]
       public string SchoolId { get; set; }
   }
    
    
//MongoDbBase是ORM自带的一个类，方便你不定义主键
public class MongoDbBase
{
    [SugarColumn(IsPrimaryKey = true, IsOnlyIgnoreInsert = true, ColumnName = "_id")]
    public string Id { get; set; }
}

2、CRUD用例

2.1 插入

//插入无返回值
db.Insertable(data).ExecuteCommand();
 
//插入并将主键赋值到实体
db.Insertable(data).ExecuteCommandIdentityIntoEntity();
 
//插入返回IDS
var ids= db.Insertable(data).ExecuteReturnPkList<string>();

2.2 查询

MongoDb一般是单表操作比较多，官方并不推荐联表操作一般用json做嵌套文档比较多

不过SqlSugar也支持了联表

//简单查询
var data2 = db.Queryable<Student>().Where(it => it.Book.Price == 1).ToList(); 
 
//分页
var count = 0;
var list = db.Queryable<School>().OrderBy(it=>it.Name).ToPageList(1,2,ref count); 
 
//json类型（实体定义isjson）
var data2 = db.Queryable<Student>().Where(it => it.Book.Price == 1).ToList();
 
//简单联表（目前只能支持这种基本联表）
var list = db.Queryable<Student>()
  .LeftJoin<School>((x, y) => x.SchoolId == y.Id)
  .LeftJoin<School>((x, y, z) => x.SchoolId == z.Id)
  .Where((x, y) =>y.Name == "TestSchool")
  .Select((x, y,z) => new
  {
      StudentName = x.Name,
      SchoolName = y.Name,
      SchoolName2=z.Name
  }).ToList();
   
 //简单分组查询
   var list14 = db.Queryable<OrderInfo>()
     .GroupBy(it => new { it.Name ,it.Price })
     .Select(it => new
     {
         key = it.Name,
         Prie=it.Price,
         groupCount = SqlFunc.AggregateCount(it.Id),
         max = SqlFunc.AggregateMax(it.Id),
         min = SqlFunc.AggregateMin(it.Id)
     }).ToList(); 
      
  //目前不支持导航查询和子查询

2.3 删除

//根据主键岀队string [] ids= [...]
db.Deleteable<Student>().In(ids).ExecuteCommandAsync() 
//根据实体删除,实体要有主键 var delrow = db.Deleteable(data).ExecuteCommand();

2.4 更新

 var updateRow2 = db.Updateable(new List<OrderInfo>() 
   {
       new OrderInfo() { Id = ids.First(),Name="a31",Price=11},
       new OrderInfo() { Id = ids.Last(),Name="a41"}
   })
  .ExecuteCommand();
  
   var updateRow3= db.Updateable<OrderInfo>()
    .SetColumns(it=>it.Name=="xx")
    .Where(it=> it.Id == id)
   .ExecuteCommand();

2.5 使用原生SQL

db.Ado.ExecuteCommand(@"insertMany UnitSchool123131  [{ ""Name"" : ""XX大学"" }]");
 
//C#对象构造  
var documents = new[]
{
    new BsonDocument { { "Name", "XX大学" } }
}; 
var bsonArray = new BsonArray(documents).ToJson();
var cmd = $"insertMany UnitSchool123131 {json}";
db.Ado.ExecuteCommand(cmd);
 
 
//查询
 var list=db.Ado.SqlQuery<T>(cmd);
 var dt=db.Ado.GetDataTable(cmd);
  
  
//sqlsugar中获取原生对象
IMongoDatabase rdb= ((MongoDbConnection)db.Ado.Connection).GetDatabase(); 
//IMongoDatabase 是什么东西？
//var client = new MongoClient("mongodb://localhost:27017");
//IMongoDatabase database = client.GetDatabase("TestDatabase");

 

3、源码DEM

https://github.com/DotNetNext/SqlSugar 

DEMO 下载 ： https://github.com/DotNetNext/SqlSugar