Now that we have seen how to configure the generation of a database with DataAnnotation, we’ll see how to do the same, and more, with Declare a property as foreign key with Code Fluent Here is the first operation we can’t do using DataAnnotations. It asks us to specifyĪn action in case of delete (to avoid multiple cascade delete) or to modify our constraints.Īs we don’t want to modify our constraints, we will specify an action in case of delete. It estimates there will be some issues if we let it as is. It doesn’t want to create tables and constraints because This error doesn’t come from Entity Framework or Code First, it comes from SQL Server. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modifyĬould not create constraint. On table 'Tasks' may cause cycles or multiple cascade paths. Introducing FOREIGN KEY constraint 'FK_Tasks_Projects_ProjectId' Here is how to do it using DataAnnotations: So we will define a maxĪlso indicate that a project should have a name. It’s not really useful and we don’t want the Name of the project to be so long. The string type in our class are nvarchar(max). If we take a look at the table Project, we can see that all our columns created from Define MaxLength of a column using DataAnnotationįirst, we will define our columns. The first one is using Data Annotations as we have seen on my second post about foreign key relationships, In Code First, there are two ways for configuring database creation. Now that we have learnt how to create a database with Code First and howĪ foreign key relationship, let's see what else can be configured. In this article, we are going to see how to use Data Annotations and Code Fluent to tweak our database. In a second one, I explain how to declare foreign keys forĬode First: EF Code First: Add a foreign key relationship. How to generate a table using EF Code First. We saw in a first article, EF Code First: Let's try it,
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