雖然c#的mongo 驅動很強大，而且還支援linq，但是一些複雜的操作語句還是比較困難

下面用Bson實現功能

• 這是模型(我這裡有多層巢狀)

• public class CtStreetPurpose
      {
         
          public long Id { get; set; }
  
          public List<StreetPurpose> StreetPurposes { get; set; }
      }
  
   public class StreetPurpose
      {
          public long BuyerId { get
   
  ; set; }
  
          public string Remark { get; set; }
  
          public string RemarkName { get; set; }
  
          public List<PurposeStreetId> StreetIds { get; set; }
        
          public string PurposeCategory { get; set; }
  
          public int Top { get; set; }
  
          public string Content { get
   
  ; set; }
       
          public long FollowTime { get; set; }
  
         
          public long UpdateTime { get; set; }
   }
  
  public class PurposeStreetId 
      {
   
          public long Id { get; set; }
  
          public long StreetId { get; set; }
     }
  　　

直接上程式碼

public async Task UpdateStreetPurpose(CtStreetPurpose create)
        {
 

           var writeModels = new List<WriteModel<CtStreetPurpose>>();
  
            foreach (var purpose in create.StreetPurposes)
            {
                //過濾條件
                var filter = new BsonDocument
                {
                    {"_id",create.Id},//在monogo db 裡面id是_id
                    //第一層巢狀中的欄位過濾
                    {
                        "StreetPurposes",new BsonDocument
                        {
                            {"$elemMatch",new BsonDocument{{ "BuyerId", purpose.BuyerId}}}
                        }
                    },
                };
               
               //構建一個bson陣列存放需要插入集合的資料
                var streetIdsBsonArray = new BsonArray();
                foreach (var streetIds in purpose.StreetIds)
                {
                    var streetIdsBson = new BsonDocument
                    {
                        {"_id", streetIds.Id},
                        {nameof(PurposeStreetId.StreetId), streetIds.StreetId}
                    };
                    streetIdsBsonArray.Add(streetIdsBson);
                }

                //更新
                var update = new BsonDocument
                {
                    {
                        //插入集合
                        "$push",new BsonDocument
                        {
                            {
                                //如果不是插入集合--這裡需要修改
                                "StreetPurposes.$.StreetIds",new BsonDocument
                                {
                                    {"$each",streetIdsBsonArray}
                                }
                            }
                        }
                    }
                };
               

                writeModels.Add(new UpdateManyModel<CtStreetPurpose>(filter, update) { IsUpsert = true });  // IsUpsert--強制更新

            } 

          await collection.BulkWriteAsync(session, writeModels); 
}

第一次寫問隨筆沒什麼經驗 ^ - ^