MongoDB 系列(一) C# 类似EF语法简单封装

之前写过一篇关于MongoDB的封装 发现太过繁琐 于是打算从新写一篇简易版

1：关于MongoDB的安装请自行百度,进行权限认证的时候有一个小坑,3.0之后授权认证方式默认的SCRAM-SHA-1模式,

需要首先命令创建一个用户,然后Drop掉这个用户,然后修改system.version里的authScheam为3,在没有创建用户的情况下

authScheam的值貌似是查询不到的。

修改成3后,授权验证方式就变成了MONGODB-CR

 2：建立一个聚合根和实体

 public interface ICore
    {
        string Id { set; get; }
    }

    /// <summary>
    /// 聚合根
    /// </summary>
    public interface IAggregateRoot
    {
         string Id { set; get; }
    }

    /// <summary>
    /// 实体
    /// </summary>
    public abstract class Core : ICore
    {
        public string Id { set; get; } = Guid.NewGuid().ToString();
    }

3：建立实体

/// <summary>
    /// 用户
    /// </summary>
    public class User : Core, IAggregateRoot
    {
        /// <summary>
        /// 名字
        /// </summary>
        public string Name { set; get; }

        /// <summary>
        /// 身份证
        /// </summary>
        public string Cardcertificate { set; get; }

        /// <summary>
        /// 性别
        /// </summary>
        public Gender Gender { set; get; } = Gender.Boy;

        /// <summary>
        /// 用户的房屋信息
        /// </summary>
        public List<House> Houses { set; get; } = new List<House>();
    }


    public class House : Core
    {
        public string Adress { set; get; }
    }

    public enum Gender
    {
        Boy = 0,
        Gril = 1
    }

4：建立一个接口Context似于EF的DBContext

    public interface IMongoDBContext
    {
        

        /// <summary>
        /// 具体的表连接器
        /// </summary>
        /// <typeparam name="K"></typeparam>
        /// <returns></returns>
       IMongoCollection<K> DbSet<K>() where K : IAggregateRoot;


    }

添加一个接口的实现

Client 表示的是Mongodb客户端驱动链接 类似于ADO里的SqlConnection

DataBase 表示的是具体的数据库

DbSet 指定具体的表

MongoCredential 认证授权的加密方式

3：建立一个具体的DBContext

BasicContext  类似于EF里面大家直接链接具体库的DBContext

Users User表的映射

4：建立一个MongoDB访问的扩展类

    public static class MongodbExpansion
    {
        /// <summary>
        /// 单个对象添加
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="collection"></param>
        /// <param name="entity"></param>
        public static void Add<T>(this IMongoCollection<T> collection, T entity) where T : IAggregateRoot
            => collection.InsertOne(entity);

        /// <summary>
        /// 集合添加
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="collection"></param>
        /// <param name="entitys"></param>
        public static void AddRange<T>(this IMongoCollection<T> collection, List<T> entitys) where T : IAggregateRoot
            => collection.InsertMany(entitys);


        /// <summary>
        /// entity mongodb需要更新的实体 properts需要更新的集合属性,大小写不限 默认更新整个对象 replace 默认空属性不修改
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="collection"></param>
        /// <param name="entity">mongodb需要更新的实体</param>
        /// <param name="properts">需要更新的集合属性,大小写不限 默认更新整个对象 </param>
        /// <param name="replace">默认对象属性为空时不替换当前值</param>
        public static void Update<T>(this IMongoCollection<T> collection, T entity, List<string> properts = null, bool replace = false) where T : IAggregateRoot
        {
            if (entity == null)
                throw new NullReferenceException();

            var type = entity.GetType();
            ///修改的属性集合
            var list = new List<UpdateDefinition<T>>();

            foreach (var propert in type.GetProperties())
            {
                if (propert.Name.ToLower() != "id")
                {
                    if (properts == null || properts.Count < 1 || properts.Any(o => o.ToLower() == propert.Name.ToLower()))
                    {
                        var replaceValue = propert.GetValue(entity);
                        if (replaceValue != null)
                        {
                            list.Add(Builders<T>.Update.Set(propert.Name, replaceValue));
                        }
                        else if (replace)
                            list.Add(Builders<T>.Update.Set(propert.Name, replaceValue));
                    }
                }
            }
            #region 有可修改的属性
            if (list.Count > 0)
            {
                ///合并多个修改//new List<UpdateDefinition<T>>() { Builders<T>.Update.Set("Name", "111") }
                var builders = Builders<T>.Update.Combine(list);
                ///执行提交修改
                collection.UpdateOne(o => o.Id == entity.Id, builders);
            }
            #endregion

        }

        /// <summary>
        /// 移除根据ID
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="collection"></param>
        /// <param name="entity"></param>
        public static void Remove<T>(this IMongoCollection<T> collection, T entity) where T : IAggregateRoot
        => collection.DeleteOne(o => o.Id == entity.Id);

        /// <summary>
        /// 移除表达式
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="collection"></param>
        /// <param name="expression"></param>
        public static void Remove<T>(this IMongoCollection<T> collection, Expression<Func<T, bool>> expression) where T : IAggregateRoot
        => collection.DeleteOne(expression);

        public static IFindFluent<T, T> Where<T>(this IMongoCollection<T> collection, Expression<Func<T, bool>> expression)
        => expression == null ? collection.Find(Builders<T>.Filter.Empty) : collection.Find(expression);

        /// <summary>
        /// MongoDB里面是没有实现IQueryable的 所以想要使用习惯的SELECT我们只能自己封装一下
        /// </summary>
        /// <typeparam name="TDocument"></typeparam>
        /// <typeparam name="TProjection"></typeparam>
        /// <typeparam name="TNewProjection">返回新的数据类型</typeparam>
        /// <param name="IQueryable"></param>
        /// <param name="projection"></param>
        /// <returns></returns>
        public static IFindFluent<TDocument, TNewProjection> Select<TDocument, TProjection, TNewProjection>(this IFindFluent<TDocument, TProjection> IQueryable, Expression<Func<TDocument, TNewProjection>> projection)
        => IQueryable.Project(projection);


        /// <summary>
        /// 获得筛选后的首个元素
        /// </summary>
        /// <typeparam name="TDocument"></typeparam>
        /// <typeparam name="T"></typeparam>
        /// <param name="IQueryable"></param>
        /// <returns></returns>
        public static T FirstOrDefault<TDocument, T>(this IFindFluent<TDocument, T> IQueryable)
         => IQueryable.First();


        /// <summary>
        /// 直接支持表达式树后的首个满足对象
        /// </summary>
        /// <typeparam name="TDocument"></typeparam>
        /// <typeparam name="T"></typeparam>
        /// <param name="collection"></param>
        /// <param name="expression"></param>
        /// <returns></returns>
        public static T FirstOrDefault<TDocument, T>(this IMongoCollection<T> collection, Expression<Func<T, bool>> expression = null)
        => expression == null ? collection.Find(Builders<T>.Filter.Empty).First() : collection.Find(expression).First();
    }

Builders<T>.Update.Combine 方法是将多个UpdateDefinition<T>修改设置合并成一个builder对象执行

IFindFluent 所返回的都是MongoDB执行的命令

MongoDB客户端驱动也是支持异步操作的我这里就没有写了 有兴趣的可以自己研究下

5：建立测试仓储

6：仓储的实现  是不是看起来有点EF的感觉？ ~0~

7：建立Service接口

8 领域服务的实现

9：单元测试用例

 BasicContext Context = new BasicContext();
            Context.Users.Add(new Entity.User()
            {
                Name = "小七子",
                Cardcertificate = "123456789",
                Gender = Entity.Gender.Boy,
                Houses = new System.Collections.Generic.List<Entity.House>() { new Entity.House() { Adress = "中关村110号双拼别墅" } }
            });

            Context.Users.Where(o => o.Cardcertificate == "110").ToList();

            Context.Users.Update(new Entity.User() { });

            Context.Users.Remove(new Entity.User() { });

            Context.Users.Where().Select(o => o.Name).ToList();
            Console.ReadKey();