Can you use Entity Framework for validation in MVC?
The validation API in Entity Framework plays very nicely with client side validation in MVC but you don’t have to rely on client-side validation. Entity Framework will take care of the validation on the server side for DataAnnotations or configurations you’ve applied with the code first Fluent API.
Where do I find ivalidatableobject in Entity Framework?
IValidatableObject is an interface that lives in System.ComponentModel.DataAnnotations. While it is not part of the Entity Framework API, you can still leverage it for server-side validation in your Entity Framework classes.
What does validation failed for one or more entities mean?
EntityValidationErrors is a collection which represents the entities which couldn’t be validated successfully, and the inner collection ValidationErrors per entity is a list of errors on property level. These validation messages are usually helpful enough to find the source of the problem. A few slight improvements:
How are validations respected at the data entity level?
The validations are respected by data entities that are built by using those tables. Although these validations are intrinsic to the tables that back a data entity, validations can also be defined at the data entity level.
How to specify validations when using code first?
When using code first, you can specify validations using annotation or fluent API configurations. Additional validations, and more complex, can be specified in code and will work whether your model hails from code first, model first or database first. I’ll demonstrate the validations with a simple pair of classes: Blog and Post.
What happens when the title field is required in Entity Framework?
The error message “The Title field is required” will be displayed as before. Except now it will be a result of server-side validation. Entity Framework will perform the validation on the Required annotation (before it even bothers to build an INSERT command to send to the database) and return the error to MVC which will display the message.