Data annotations composite key12/14/2023 You can also map and configure the properties of your domain classes using Fluent API. The Property method is used to obtain a configuration object for a given property. The Property method is used to configure attributes for each property belonging to an entity or complex type. When the database is generated you see the following tables in your database as shown in the following image. StudentEnrollmentInfo − Contains EnrollmentDate. StudentData − Contains Student FirstMidName and Last Name. In the above code, you can see that Student entity is split into the following two tables by mapping some properties to StudentData table and some properties to StudentEnrollmentInfo table using Map method. ModelBuilder.Entity().ToTable("EnrollmentInfo") ModelBuilder.Entity().ToTable("CourseDetail") Data Annotations - Key Attribute in EF 6 & EF Core. In such cases, you would use the fluent API to explicitly specify that a type is a complex type. In this chapter, we will continue with the simple example which contains Student, Course and Enrollment classes and one context class with M圜ontext name as shown in the following code. Configures the primary key property(s) for this entity type. There are some scenarios where Code First will not detect a complex type (for example, if you do have a property called ID, but you do not mean for it to be a primary key). RequiredAttribute: Specifies that a data field value is required. RegularExpressionAttribute: Specifies that a data field value in ASP.NET Dynamic Data must match the specified regular expression. We also need to use Spring JpaRepository to achieve our goal. Hence well be using EmbeddeId and Embeddable annotations to represent composite keys in JPA entities. RangeAttribute: Specifies the numeric range constraints for the value of a data field. In this tutorial, were going to cover the use of the EmbeddedId annotation and findBy method for querying a composite key based JPA entity. Fluent API supports the following types of mappings. Specifies that a data field value is a well-formed phone number. In Entity Framework, we can use it to create Composite Primary key, while in EF Core it is not supported. This attribute is applicable to both Entity Framework & Entity Framework Core. The Code First Fluent API is most commonly accessed by overriding the OnModelCreating method on your derived DbContext.įluent API provides more functionality for configuration than DataAnnotations. Data Annotations Key Attribute in EF Core The Key Attribute or Primary key attribute maps the property as the primary key column in the database. Data annotations and the fluent API can be used together, but Code First gives precedence to Fluent API > data annotations > default conventions.įluent API is another way to configure your domain classes. And it will still generate Fluent API so EF Core is also happy.Fluent API is an advanced way of specifying model configuration that covers everything that data annotations can do in addition to some more advanced configuration not possible with data annotations. Then your scaffolding code would KeyAttribute for composite key so OData is happy. You can copy this file and change below code and replace the service to get behavior you desire.Īll you need is to remove the check for 1 property. If you want to got bit crazy (warning: internal code so it can break between EF core releases): But I was commenting that it would not be good idea to EF to write some code which can be misleading. It is just matter of scaffolding KeyAttribute which would be ignored by EF. In your particular case, we can scaffold the code which would work with OData & it would still work with EF Core. This issue particularly talks about support for KeyAttribute at runtime. I just wanted to clarify 2 different aspect.
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