The delete behavior configured in the EF Core model is only applied when the principal entity is deleted using EF Core andthe dependent entities are loaded in memory (that is, for tracked dependents). A corresponding cascade behavior needs to be setup in the database to ensure data that is ...
在EF Core 3.0 之前,CustomerId 属性将按约定用于外键。但是,如果 Order 是从属类型,那么这也会使 CustomerId 成为主键,这通常不是预期结果。新行为自3.0 起,如果外键的主体属性名称相同,EF Core 不会尝试通过转换来为外键使用属性。与主体属性名称关联的主体类型名称和与主体属性名称模式关联的导航名称仍然相匹配。
在EF Core 3.0 之前,CustomerId 属性将按约定用于外键。但是,如果 Order 是从属类型,那么这也会使 CustomerId 成为主键,这通常不是预期结果。新行为自3.0 起,如果外键的主体属性名称相同,EF Core 不会尝试通过转换来为外键使用属性。与主体属性名称关联的主体类型名称和与主体属性名称模式关联的导航名称仍然相匹配。
I have a test database where I set theDeleteBehaviourof one line toRestrict. When I reverse engineer it theDeleteBehaviouris set toClientSetNull. As the foreign key isn't nullableClientSetNullseems an odd result. Steps to reproduce My DbContext looks like this publicclassEfCoreContext:DbContext...
Change one or more of the relationships to not cascade delete. Configure the database without one or more of these cascade deletes, then ensure all dependent entities are loaded so that EF Core can perform the cascading behavior.Taking the first approach with our example, we could make the ...
DeleteBehavior 在 OnDelete 中的值 a. Cascade(默认) 删除相关实体 b. ClientSetNull, SQL抛出异常, 不可以设置外键字段为 null c. SetNull, , SQL抛出异常, 不可以设置外键字段为 null d. Restrict, 不进行任何改变 EFCore 抛出异常, 子实体的外键不发生改变, 引用了删除的实体 ...
(1) EFCore删除必须先查询再删除,优化后可直接删除:context.User.Where(t => t.Id == 100).Delete(); (2)优化更新语句:context.User.Where(t => t.Id == 4).Update(t =>new User() { NickName = "2224114" ,Phone = "1234"} );
include 太多的情况下, split query 可能性能会好一些. 所以 ef core 让我们自己调. 也可以像 AsTracking 那样调 global o => o.UseQuerySplittingBehavior(QuerySplittingBehavior.SplitQuery) 2. Filtered include include 之前是写不了 filter 的. 现在总算可以了 ...
(1) EFCore删除必须先查询再删除,优化后可直接删除:context.User.Where(t => t.Id == 100).Delete(); (2)优化更新语句:context.User.Where(t => t.Id == 4).Update(t =>new User() { NickName = "2224114" ,Phone = "1234"} );
Data annotations is a much easier way to configure model than Fluent API. And we can only configure DeleteBehavior via Fluent API today, that means we need configure foreign key again in fluent api. Can we have a DeleteBebaviorAttribute(...