Question

我有一个应用程序可以根据价格进行大量计算，目前需要约87秒。基于时间表，我怀疑我使用我的包含的方式对于实体框架非常不理想，并且我可以做出重大改进。

我的时间表是这样的：

0秒 - 接收GET请求
2秒 - 向SQL Server发送查询（查询所有必要的内容，其结果是> 40.000个字符。我添加了一些部分问题的底部）
5秒 - 从SQL Server接收查询结果
45某个帖子正在退出
46某个帖子正在退出
50一些线程正在退出
80关闭SQL连接（我认为将查询结果映射回我的C＃类需要EF6~75秒，但我不确定）
80次开始计算
87所有计算完成

查询的设计大多是这样的

var result = await db.MyAuthorizedFooExtension()
    .Include(x => x.Foofie)
    .Include(x => x.Bar.Baz)
    .Include(x => x.FooFoo.Select(y => y.BarBar))
    .Include(x => x.FooFoo.Select(y => y.BazBaz))
//etc.
    .ToListAsync()

结果如下：

[UnionAll7].[C9] AS [C55], 
...
   FROM  (SELECT 
        CASE WHEN ([Join2].[ID1] IS NULL) THEN CAST(NULL AS int) ELSE 1 END AS [C1], 
        [Extent1].[ID] AS [ID], 
...
        [Join2].[ID1] AS [ID5], 
...
        CAST(NULL AS varchar(1)) AS [C4], 
...
        FROM   [dbo].[Contract] AS [Extent1]
        INNER JOIN [dbo].[Leverancier] AS [Extent2] ON [Extent1].[Leverancier] = [Extent2].[ID]
        LEFT OUTER JOIN  (SELECT [Extent3].[ID] AS [ID1], [Extent3].[Contract] AS [Contract], [Extent3].[ContractStatusOud] AS [ContractStatusOud], [Extent3].[ContractStatusNieuw] AS [ContractStatusNieuw], [Extent3].[MutatieDatumTijd] AS [MutatieDatumTijd], [Extent3].[Medewerker] AS [Medewerker], [Extent3].[Status] AS [Status1], [Extent3].[LastModifiedDate] AS [LastModifiedDate1], [Extent3].[LastModifiedBy] AS [LastModifiedBy1], [Extent4].[ID] AS [ID2], [Extent4].[Naam] AS [Naam], [Extent4].[WindowsNaam] AS [WindowsNaam], [Extent4].[Rol] AS [Rol], [Extent4].[Unit] AS [Unit], [Extent4].[Status] AS [Status2], [Extent4].[LastModifiedDate] AS [LastModifiedDate2], [Extent4].[LastModifiedBy] AS [LastModifiedBy2]
            FROM  [dbo].[ContractWijzigingHistorie] AS [Extent3]
            INNER JOIN [dbo].[Medewerker] AS [Extent4] ON [Extent3].[Medewerker] = [Extent4].[ID] ) AS [Join2] ON [Extent1].[ID] = [Join2].[Contract]
        WHERE ( EXISTS (SELECT 
            1 AS [C1]
            FROM [dbo].[Contract] AS [Extent5]
            WHERE ( EXISTS (SELECT 
                1 AS [C1]
                FROM [dbo].[Leverancier] AS [Extent6]
                WHERE [Extent6].[ID] = [Extent5].[Leverancier]
            )) AND ([Extent5].[ID] = [Extent1].[ID])
        )) AND ([Extent1].[Status] IN (1)) AND ((DATEPART (year, [Extent1].[Startdatum])) <= @p__linq__0) AND ((DATEPART (year, [Extent1].[Einddatum])) >= @p__linq__1)
    UNION ALL
        SELECT 
        2 AS [C1], 
        [Extent7].[ID] AS [ID], 
...
        CAST(NULL AS int) AS [C9], 
        CAST(NULL AS datetime2) AS [C10], 
...
        [Extent9].[PeriodeWaarde] AS [PeriodeWaarde], 
...
        [Project9].[LastModifiedBy] AS [LastModifiedBy], 
...
        [UnionAll5].[ID2] AS [C60], 
...
        CAST(NULL AS int) AS [C62], 
...
etc.

如何在仍使用Entity Framework的同时提高性能？

Answer 1

在得到查询结果后，这会引发你在做什么的问题？如果您宣读了您的查询，您将看到您在热切地加入相关表格的同时获得了所有结果。

如果在从查询中检索数据后过滤掉这些数据，那么您应该在实现数据之前过滤数据（调用ToList）。你还需要打电话给相关的桌子吗？您还应该只从数据库中选择您将使用的列。

现在，再次了解您希望自己的方法做什么会更容易。创建一个新对象或匿名对象以选择：

var result = await db.MyAuthorizedFooExtension()
//etc.
.Select(s => new
{
    Id = s.Id,
    FooName = s.FooName,
    BazId = s.Bar.Baz.Id
}
.ToListAsync();

最后实现。如果在可选方案中需要包含，请使查询成为IQueryable，最后执行逻辑并实现。

使用Entity Framework提高大型查询的性能

1 个答案: