An ORM from Microsoft that enables the code developers to work with specific domain objects, one which terminates the extra code written in the data access layer. Coding can be a tedious task. Writing ADO.NET code and managing it is a daunting job. Thus, in order to avoid this tiring task, Microsoft has provided us with a solution – Entity Framework. Entity Framework reduces a great deal of code by enabling to work with relational data as domain specific objects.
It allows developers to downsize map between various objects in software with the help of tables and columns. It uses objects of domain-specific classes but does not focus on the original database tables and columns that store the data. This allows ease in working with an abstraction of a greater level while creating and maintaining all of the data-oriented applications.
One of the other important things to be noted while answering entity framework interview questions is the multiple approaches with which it can be seen, namely- Database first, Model first and Code first.
Database first is utilised in making an entity model from an existing database and further decreasing the amount of code that needs to be written. The code first approach of entity framework signifies the permission to create a model and its relations with the help of classes, one from which the database is created; thus, assisting the developer in working in an object-oriented manner without worrying about the structure of the database. According to the model first approach of entity framework, the model classes and their relationships are first created with the help of an ORM. Then the physical database is generated by using the model. Thus, the diagram of entity and relations is converted into the requisite code model.
The suitability of any model depends mostly on the project undertaken. If the database is present, then it is usually wise to go with the Database First approach. If model classes and database are absent, the Model First is the most suitable. If the developer has domain classes, the Code First approach is the stands to be most suitable.
The entity framework comes with its own set of advantages and disadvantages for any coder. The advantages include:
- It can shorten codes with the help of alternate commands making the job of developers simpler.
- It has brilliant prototypes that allow writing of object-oriented codes.
- It allows auto migrations that make setting up or modifying a database easy and much less time consuming.
On the other hand, its disadvantages include:
- Entity Framework is a much slower form of Object Relational Mapper.
- It directs the shape of the model, especially for more complex projects. Also, cleaning a model is not without an ORM technology.
- Sometimes things can become complicated, especially if the developer is not using raw SQL codes.
Situations several users access and alter the same data in a particular database, at the same time, this activity known as Database concurrency. In Entity Framework, the core is responsible for implementing such controls by allowing changes independently minus the synchronization.
In an ideal case, the changes do not interfere with each other. In other cases, the changes might be conflicting changes, and only one must succeed.
Entity Framework is an additional layer between application and database that enables the developers to program against the conceptual application model instead of programming directly against the relational storage schema. Every entity must have a key, even in the case where the entity maps to a view. When you use the Entity Designer to create or update a model, the classes that are generated inherit from EntityObject, which requires EntityKey. So, we have to have a primary key in the table to add it to the data model.
The Entity Framework is a component of the .NET Framework so Entity Framework applications can run on any computer on which the .NET Framework starting with version 3.5 SP1 is installed.
The Entity Data Model (EDM) is a set of concepts that describe the structure of data, regardless of its stored form. The EDM borrows from the Entity-Relationship Model described by Peter Chen in 1976, but it also builds on the Entity-Relationship Model and extends its traditional uses.
The EDM addresses the challenges that arise from having data stored in many forms. For example, consider a business that stores data in relational databases, text files, XML files, spreadsheets, and reports.
This presents significant challenges in data modelling, application design, and data access. When designing a data-oriented application, the challenge is to write efficient and maintainable code without sacrificing efficient data access, storage, and scalability.