EF Core – 继承 Inheritance 摘要:前言 继承是面向对象里的概念. 关系数据库只有一对一, 一对多这类关系, 并没有 "继承" 关系的概念. 所以 ORM (Object–relational mapping) 就需要搞一些规则来映射出它. 这篇就说说 EF Core 如果映射继承关系. 题外话: 继承不顺风水, 尽量少用, 我的从前 阅读全文 ...
Inheritance Search .NET data Entity Framework Entity Framework EF Core & EF6 Entity Framework Core Welcome! What's new in EF Core 9.0 Breaking changes in EF Core 9.0 Getting started Releases and planning (roadmap) DbContext configuration and initialization...
Previously, discriminator columns created forTPH inheritance mappingwere configured asnvarchar(max)on SQL Server/Azure SQL, or the equivalent unbounded string type on other databases. New behavior Starting with EF Core 8.0, discriminator columns are created with a max length that covers all the known...
publicabstractclassAnimal {publicintId {get;set; }publicstringSharedField {get;set; } ="";publicstringType {get;set; } ="";//加入一个 Type 替代默认的 Discriminator} 配置 modelBuilder.Entity<Animal>().UseTphMappingStrategy() .HasDiscriminator(e=>e.Type) .HasValue<Cat>("MyCat") .HasValue...
EF Core 与ASP.NET Core 不存在严密的挂钩(因为EF Core 在ASP.NET之外还有很多运用场景),但它是ASP.NET Core不可或缺的一部分,因此在发布ASP.NET Core时,我们必须提供一个稳定的EF Core 版本,这很重要! Features(特性) 因为EF Core 是一个新的代码库(译注:完全重写),因此,之前版已有的一些特性在EF Core...
Code is generated using T4 templates so can be customized to suit any needs. It supports inheritance, unidirectional and bidirectional associations, enumerations, and the ability to color-code your classes and add text blocks to explain potentially arcane parts of your design. For EF Core: 2-8...
Next, it uses the schema information to create an EF Core model. Tables are used to create entity types; columns are used to create properties; and foreign keys are used to create relationships. Finally, the model is used to generate code. The corresponding entity type classes, Fluent API,...
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 ...
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 ...
TPH (Table-Per-Hierarchy) inheritance model can be set in 2 ways. First is automatically by Convention, in which case the Discriminator column is not directly in the Entity but is Shadow Property. And second is to explicitly define Discriminator property in Entity and configure it with .Has...