ASP.Net MVC 6 线程优化[关闭]

Question

寻求有关使用 Thread 的建议。

我有控制器，它在数据库中查询并在列表中转换选定的数据。但在某些情况下，我需要多行的额外信息。我不想为每一行循环新查询。 如果我将启动新线程，它将与我的主循环并行执行额外查询并向列表添加额外信息。好与不好。或者最好先获取所有数据。

示例：

    [HttpPost]
      public async Task<IActionResult> ReestrRazr(DateTime date)
      {
        List<SomeClass> arr = new List<SomeClass>();
 string query = " SELECT [table].[id], [table].[snumber], [table].[datein], [table].[datefileeate], [table].[istatusU], [table].[datezamechania], [table].[type], [table].[isubtypeU], ";
                query += " [tableT3040].[content] as [address], [tableT3040].[nazvanie] as [objNazvanie], ";
                query += " [tableT101].[nazvanie] as zastrName, ";
                query += " [adress].[rajon], ";
                query += " [objT3].[idcomlinknypredstavitelpurpose] as [nadzor] ";

                query += " FROM ((((((((([table] ";
                query += "  JOIN [link] on (([table].[id]=[link].[idlinkper]) and ([link].[ideletestate]=0)) ) ";
                query += " JOIN [file] on (([file].[id]=[link].[idlink]) and ([file].[sfileextension] like ('%pdf%')) and ([file].[ideletestate]=0)) ) ";
                query += " JOIN [obj] ON ([table].[identity]=[obj].[id] AND [obj].[ideletestate]=0)  ) ";
                query += " LEFT JOIN [objT] as [objT3] on (([objT3].[identity]=[obj].[id]) and ([objT3].[type]=3) and ([objT3].[ideletestate]=0)) )";
                query += " LEFT JOIN [adress]  ON (([obj].[idaddress]=[adress].[id]) and ([adress].[ideletestate]=0) and ([adress].[workstate]=1)) ) ";
                query += " LEFT JOIN [objT] as [objT119] on (([objT119].[identity]=[obj].[id]) and ([objT119].[type]=119) and ([objT119].[ideletestate]=0) and ([objT119].[idcomlinknypredstavitelpurpose] = 1)) )";
                query += " LEFT JOIN [tableT] as [tableT3040] on (([table].[id]=[tableT3040].[idlinkper]) and ([tableT3040].[type]=3040) and ([tableT3040].[ideletestate]=0)) ) ";
                query += " LEFT JOIN [tableT] as [tableT101] on (([table].[id]=[tableT101].[idlinkper]) and ([tableT101].[type]=101) and ([tableT101].[nazvanie] <> '') and ([tableT101].[nazvanie] is not null) and ([tableT101].[ideletestate]=0)) )";
                query += " left join [ae] on (([table].[idcomlinkny]=[ae].[id]) and ([ae].[ideletestate]=0)) ) ";
        DataTable dt = Execute4Table(query + $" where date >'{date.tostring("yyyyMMdd")}'")
        foreach (DataRow row in dt.Rows)
        {
          int id = Convert.ToInteger(row[0]);
          int type = Convert.ToInteger(row[1]);
          string number= Convert.ToString(row[2]);
         
          SomeClass sc = new SomeClass();
          sc.id=id;
          sc.number = number;
    
          if (type==50)
           {
            number = Convert.ToString(ExecuteScalar("select number from table WHERE idparent="+ id.tostring()));
           }
    
          arr.Add(sc);
        }
    }

谢谢！（对不起我的英语） 附：真正的查询有 8 个 JOIN，获得所有必要的信息将导致 JOIN 的数量增加到 12-13 个。这对性能不利。

Answer 1

您将无法从同一个 DbContext（请求范围）运行并行查询。我会为一个查询执行left outer join，该查询将为您带来您需要的所有数据，其他行的空值或允许客户端对这些行发出额外的请求，请求/行。尽管我会坚持第一个想法，只要事实证明这些“额外”不会导致查询的基本版本急剧变慢。 3ed 选项是主查询只使用await，从内存结果中收集选定的ID，然后使用IN 进行第二次查询，处理稍后在内存中分配值。