正如其他人在comments中所说的那样，您可以使用EF6 code来解析表达式并应用相关的Include/ThenInclude调用...
EF Core 不支持在同一上下文实例上运行多个并行作。 在开始下一个操作之前,您应始终等待当前操作完成。 这通常是通过在每个异步操作上使用await关键字来完成的。 警告 遗憾的是,Microsoft.Data.SqlClient的异步实现存在一些已知问题(例如#593、#601等)。 如果看到意外的性能问题,请尝试改用同步命令执行,尤其是在处理...
查询关联表,一级用Include二级以后用ThenInclude。 usingConsoleApp1.Data;//上下文的文件夹usingMicrosoft.EntityFrameworkCore;//ef框架using(vardb =newOAContext()) {varstu = db.Student.AsNoTracking().Include(s=>s.users).ToList();//二级三级以上往后加ThenInclude(c=>c.关联名)即可foreach(varsinstu)...
https://docs.microsoft.com/en-us/ef/core/what-is-new/ef-core-5.0/whatsnew#configure-database-precisionscale-in-model (decimal) https://docs.microsoft.com/en-us/ef/core/what-is-new/ef-core-5.0/whatsnew#filtered-include (filter + include) 更新: 2020-07-11 今天才发现的坑 sql select 的...
Alternative (not MS based) Language Integrated Query (LINQ) technology for relational databases. It allows you to use C# to write strongly typed SQL queries. For EF Core: 3-8. Full C# support for query creation: multiple statements inside lambda, variables, functions, etc. ...
类似这样的查询将在单个有效负载中从数据库中引入大型连接图表,这会加剧所有带宽问题,尤其是当有效负载中有大量冗余时(例如,使用多个级别的 Include 来遍历一对多方向中的关联时)。可以通过使用 ToTraceString 访问查询的基础 TSQL 并在 SQL Server Management Studio 中执行 store 命令来查看有效负载大小,从而检查查询...
(so if Parent {1} has Child {1,1} then Parent {2} can still have Child {2,1}). By making the foreign key part of the primary key the relationship between the owner and the owned entity becomes immutable and reflects aggregate semantics better. This is what EF Core does by default....
The [PrimaryKey] attribute was introduced in EF Core 7.0. Use the Fluent API in older versions. C# Copy [PrimaryKey(nameof(State), nameof(LicensePlate))] internal class Car { public string State { get; set; } public string LicensePlate { get; set; } public string Make { get; set;...
There is no such assumption. Rather when navigation is collection, to load nav props for each collection itemThenIncludeis required. See the examples athttps://ef.readthedocs.io/en/latest/querying/related-data.html#including-multiple-levels ...
大部分时间都花在尝试优化产生的查询上。 生成的 store 命令将包含每个 Include 的外部联接或联合,具体取决于映射。 类似这样的查询将在单个有效负载中从数据库中引入大型连接图表,这会加剧所有带宽问题,尤其是当有效负载中有大量冗余时(例如,使用多个级别的 Include 来遍历一对多方向中的关联时)。