为了避免这样的操作产生,我们要给表中的关键字段设置一个并发标记,这样,当我们出现上述问题时,数据库爆出相应异常(如DbUpdateConcurrencyException)来对数据进行保护。 SqlServer的并发冲突特性 sqlserver有两个特性来记录并发冲突: 1、TimeStamp,在efcore中的表示是一个TimeStampAttribute属性,FluentApi表示为: builder.Ent...
Entity Framework Core使用一组约定来根据实体类的形状生成模型。可指定其他配置以补充和/或替代约定的内容。常见的方式包括Fluent API方式配置 数据注释方式配置配置方式Fluent API方式配置可在DbContext的派生上下文中重写实现OnModelCreating方法,并使用ModelBuilder API来配置模型。
在一般 (“開放式”) 案例中,不會發生並行更新,而且 UPDATE 會順利完成,修改數據列:資料庫向EF Core 回報一個數據列受到UPDATE的影響,如預期般。 不過,如果發生並行更新,UPDATE 會找不到任何相符的數據列和報告,而該數據列和報告會受到影響。 因此,EF Core 會SaveChanges()擲回DbUpdateConcurrencyException,應用程...
如果您正在使用ABP框架（并且您使用框架提供的EfCoreRepository基类来实现存储库），则当您的实体实现IHas...
并行检测(也就是 EFCore 一个上下文实例只能有一个正在执行的查询语句的基石) 执行逻辑(例如失败重试) 异步任务的 CancellationToken 各种日志输出 查询参数的添加和读取 实体跟踪和状态管理 在关系型数据库驱动中, RelationalQueryContext 另外附加 数据库连接 ...
In EF Core, optimistic concurrency is implemented by configuring a property as aconcurrency token. The concurrency token is loaded and tracked when an entity is queried - just like any other property. Then, when an update or delete operation is performed duringSaveChanges(), the value of the ...
The value used for the concurrency token is typically, but does not have to be, the original value of the concurrency token property. Return the number of rows affected so that EF Core can compare this against the expected number of rows affected and throw a DbUpdateConcurrencyException if ...
But when I try to use EF core 6 again and use the Add statement on the scaffolded database model of the parent table it fails with the error Microsoft.EntityFrameworkCore.DbUpdateConcurrencyException: The database operation was expected to affect 1 row(s), but actually affected 0 row(s);...
Extension for EntityFramework and EntityFramework Core that provides: Expandable Extension Methods, Complex Types as JSON, Auditing, Concurrency Checks, Specifications and serializable Transacton Logs.DocumentationExpandable IQueryable Extensions JSON Complex Types Specification Pattern Auditable Entities Concurrency...
Check out the.NET Data Community Standupfor other examples usingUnionqueries and TPT inheritance mapping. Better use ofINqueries When the Contains operator is used with a subquery, EF Core now generates better queries using SQLINinstead ofEXISTS; aside from producing more readable SQL, in some ...