Cascade - dependents should be deleted; Restrict - dependents are unaffected; SetNull - the foreign key values in dependent rows should update to NULL ... How to set ForeignKey column name in fluent API on EF Core. It is used to express the relationship between two tables. 75. … This is typically done to help ensure the uniqueness of data. The composite key consists of ProjectId and SectionOdKey. Is there any way I can set the foreign key in EF Core without having explicitly set the properties on both entities? This is not possible in my case, since all my tables have a foreign key to it. So for EF-core only option 3 is feasible. Any time you have a 1:1 or 1:0..1 relationship, the dependent entity will take the same primary key as the principal. Also, updated to EF 1.1.0-preview1. Entity Framework Code First - Defining Foreign Keys using Data Annotations and Fluent API When using Entity Framework Code First approach, there are actually three ways to define foreign keys. So for this: The ForeignKey attribute is used to specify which property is the foreign key in a relationship.. Entity Framework Core. However, the fluent api is forcing me to create the virtual property in the ApplicationUser entity. 535. The Entity Framework Core Fluent API OnDelete method is used to specify the action which should take place on a dependent entity in a relationship when the principal is deleted.. Thanks, Ask Question Asked 4 years, 1 ... now it's about column name too. EF Core 5; Articles; Knowledge Base; Online Examples; Navigation property without foreign key, or fluent api version? The ForeignKey attribute is used to specify which property is the foreign key in a relationship. String representation of an Enum. Here is an example showing how to create a composite unique key via fluent API. It throws a run-time exception: Entity type 'Parent' has composite primary key defined with data annotations. If you want to avoid fluent api (for whatever reason #differentdiscussion) this works fantastically. To set composite primary key, use fluent API. I'm trying to give my Foreign Key column the name I want. However, if the key or foreign key properties do not follow the convention, then you can use data annotation attributes or Fluent API to configure a one-to-one relationship between the two entities. A key serves as a unique identifier for each entity instance. The OnDelete method takes a DeleteBehavior enum as a parameter:. ... EF Fluent API + two column composite uniqueness + autoincrement primary key. The Entity Framework Core Fluent API HasAlternateKey method enables you to create an alternate key by placing a unique constraint (and therefore a unique index) on a property or properties other than those that form the primary key. – Dmitry Oct 27 '16 at 16:06. The default code first convention for ForeignKey relationship expects foreign key property name match with the primary key property. Entity Framework relationship with two foreign keys. 2. c# ef-code-first ef-migrations entity-framework entity-framework-6. EF Core 2.2 - Two foreign keys to same table. In my case I needed to include an additional foriegnKey annotation on the "Match" entity, because my fields/tables have strings for PK's. Related. In the following example, the AuthorFK property in the Book entity does not follow Entity Framework Core's convention for foreign key names.Left as it is, Entity Framework Core will create an AuthorFK field and an AuthorId field which it will configure as a foreign key: Generally, you don't need to configure one-to-one relationships manually because EF Core includes Conventions for One-to-One Relationships. 925. Now without attributes, only fluent api. 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