Entity Framework is Microsoft's strategic approach to data access technology ChapTEr 1 □ GETTInG STarTED WITh EnTITY FraMEWork. 4 Solution. Let's illustrate the problem with the two tables shown in Figure Entity Framew ork Recipes anion vailable. Entity. Framework Recipes. A Problem-Solution Approach. THE EXPERT'S VOICE® peypredkoefritlec.gq Net free pdf, Download Entity Framework 4 0 Recipes A Problem Solution Approach. Experts Voice In Net Pdf, Read Online Entity Framework 4 0 Recipes A.
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entity framework 4 0 pdf. peypredkoefritlec.gq Entity Framework introduces two new features: The DbContext API is a simplified abstraction over ObjectContext and a . NET Core Recipes: A Problem-Solution Approach. John Ciliberti Creating a New peypredkoefritlec.gq Core MVC Application Using peypredkoefritlec.gq Creating a Data Access Layer Using Entity Framework Core Code First. 5 days ago Entity Framework 4 0 Recipes A Problem Solution Approach Experts Voice In [ PDF] [EPUB] Type or paste a DOI name into the text box.
The line is annotated to show the multiplicity on each end of the association. The association in Figure is a one-to-many association between Employee and Task. An Employee can have zero or more tasks. Each Task is associated to exactly one Employee.
Every EntityType has a property or set of properties that denote its EntityKey. Finally, no discussion on Entity Framework would be complete without mentioning the context object. The context object for Entity Framework is your gateway into the Entity Framework services. The context object exposes entity objects, manages the database connection, generates parameterized SQL, marshals data to and from the database, caches objects, helps maintain change tracking and materializes, or transforms, an untyped result set into a collection of strongly typed objects.
In the beginning, there was the ObjectContext object. Now, Entity Framework supports an alternate, more streamlined context object called the DbContext. The DbContext greatly simplifies the developer experience when working with Entity Framework.
Interestingly, the DbContext is a wrapper, or facade, around the ObjectContext, exposing the underlying ObjectContext functionality in an intuitive, friendly and productive way.
Clearly, the DbContext is the preferred approach for working with Entity Framework as we will demonstrate in great detail in this book.
The Code Despite a tremendous emphasis on visual design support, the Entity Framework is all about code. The models, EntityTypes, associations, mappings, and so on are ultimately expressed in concrete code that becomes part of your application. This code is either generated by Visual Studio and Entity Framework or created manually by the development team.
You can choose quite a bit about the code-generation process or the lack of it by changing various properties on your project or modifying the underlying code-generation templates. Visual Studio uses a code-generation technology called Text Template Transformation Toolkit, simply referred to as T4 templates.
The Visual Studio tooling uses T4 templates to generate, or scaffold, code automatically. The great thing about T4 template support in Visual Studio is that you can edit the templates to tailor the code-generation process to match your exact needs. This is an advanced technique, but it is necessary in some cases.
With Code First, the developer can create entity classes, mappings and context object, all without the help of a designer. Even more interesting, the development team can leverage the Entity Framework Power Tool utilities free download from Microsoft to reverse-engineer a Code First model from an existing database, foregoing the effort to have manually create the entity classes, mappings and context object.
Many of the recipes throughout the book will show you how to use Code First across specific contexts such as in n-Tier applications. Visual Studio Of course, the main tool we use when developing applications for the Windows environment is Visual Studio.
Visual Studio and its related tools and services provide for design, development, unit testing, debugging, software configuration management, build management and continuous integration, and much more. The point is that Visual Studio is a full-featured toolset. Visual Studio plays a vital role in the development of Entity Framework applications. Visual Studio provides an integrated design surface for Entity Framework models.
Using this design surface and other tools in Visual Studio, you can create models from scratch or create them from an existing database. You also have the option to completely eliminate the designer and manually craft your Entity Types and configuration.
If you have an existing database, which is the case for many of us with existing applications, Visual Studio provides tools for importing your tables and relationships into a model. This fits nicely with the real world because few of us have the luxury of developing brand-new applications.
Most of us have to extend, maintain, and evolve our existing code and databases. Alternately, you can create a model from scratch by starting with an empty design surface and adding new EntityTypes to the surface, creating both associations and inheritance hierarchies for your model.
When you are done creating the model, right-click the design surface and select Generate Database from Model. If your project team is code-centric, you can instead create a set of domain classes, including relationships and a context class and then wire up these classes to hook into the Entity Framework engine and features without having to use a designer.
Once you have created your model, changes often happen. Visual Studio provides tools for updating the model from the database. This will keep the model synchronized with changes in the database. Additionally, the Entity Framework Team also supports a tool called Code First Migrations, which can be used to keep your database up-to-date with changes in your model. In the dialog box see Figure , choose the ADO. This template is located under the Data templates. Adding a new model to your project There are two options on the first page of the Entity Data Model Wizard: start with an existing database or start with an empty model.
The Entity Data Model Wizard gives you a choice between creating a model from an existing database or starting with an empty model Generating a model from an existing database is the Database-First approach. From the tables, views, and stored procedures that you select from the underlying database, the wizard will create a model and entity classes, against which you can write code.
The immediate benefit here is that you write code against strongly typed entity classes, which Entity Framework maps to the underlying database tables and columns. If the tables you include are related in the database, these relationships will be modeled as associations. This is one way to create your model if you already have a database for your application. However, if you prefer to use the Code-First approach with an existing database, worry not.
The Entity Framework team has created tooling The Entity Framework Power Tools that reverse-engineers an existing database into domain entity classes, just as if you coded them by hand.
In the Entity Framework designer, you can start with an empty design surface. Right-click the design surface to create new EntityTypes, associations, or inheritances.
You can also drag them from the Toolbox onto the design surface. Once your model is complete, just right-click the design surface and select Generate Database from Model. This will generate a script you can use to create the database tables and relationships for the model. Entity Framework will map the classes to the underlying databases and automatically create a model in memory at runtime. The key parts of a model in the designer are shown in Figure In this model, a Customer has a one-to-many association with an Order.
Each customer may have many orders, but each order is associated with just one customer.
The Mapping Detail window also shows the mapping between the columns in the Customer table and the scalar properties in the Customer EntityType. Keep in mind that you can make the same kind of mapping configurations using the data annotations or fluent API features found in the Code First approach to using Entity Framework. In some cases, we go beyond what can be done with the designer and show you how to create models that require direct editing of the underlying.
We gain significant productivity, as we can program against objects in the model EntityTypes as you do with other objects in your application. For the model in Figure , your code uses Customer and Order in much the same way as you use other objects. If you want to insert a new customer and order into the database, you can create instances of the Customer and Order types, set the properties, add them to the in-memory context that represents the model, and call SaveChanges.
All the necessary SQL code is generated and sent to the database to insert the rows. The recipes throughout this book will show you step by step how to model just about every conceivable database scenario; how to query, insert, update, and delete using these models; and how to use Entity Framework in many kinds of applications. If, on the other hand, you have built some working models and feel comfortable with a few key modeling concepts, such as entity splitting and inheritance, you can skip this chapter.
In this chapter, we will walk you through the basic examples of modeling with Entity Framework. Modeling is the core feature of Entity Framework and what distinguishes Entity Framework from previous Microsoft data access platforms.
Once you have built your model, you can write code against the model rather than against the rows and columns in the relational database. We start off this chapter with an example of how to create a simple conceptual model, and then let Entity Framework create the underlying database.
In the remaining examples, we will show you how to create models from existing tables and relationships in your databases. Creating a Simple Model Problem You have a brand new project, and you want to create a model. To create the new model, do the following: 1.
From the templates, select ADO. Adding a new. In the first step of the wizard, choose Empty Model and click Finish. You can consider it a marketing document, because its purpose is to sell you to the prospective employer.
The ideal length for your CV is 1 page if you have under 5 years of work experience and a maximum of pages if you have more than 5 years of work experience. This was the conclusion after extensive research with recruiters and employers from various industries. Make sure to tailor your CV for each specific job opening or company and include only the information and experience that is relevant to this exact position. Writing a CV is not an easy endeavor, especially if this is your first time writing one.
By choosing one of the above pre-defined layouts, you will not have to worry about the font size, alignments, or what sections to include, among many others. What I love about this section is that the end result is nevertheless professionally crafted, easy to read and eye-catching. The common challenge I encounter in my work with ambitious professionals is the struggle to comprise many years of work experience in max. Novoresume's CV template bring some order into your professional history and moreover helps the recruiter help you.
In case you are wondering what format to choose for your CV, keep in mind that the recommended CV layout by recruiters and employers is one column, especially when the length is over one page.
The CV templates generated by novoresume. The reason behind this is that a PDF looks better across different devices and is more secure. You can use the above CV samples as an inspiration, but make sure to personalize each one for a specific job application.
Try it. It's free. CVs Senior. Here is an overview of the sections your CV needs, in the order they should appear. Head the CV with your name and contact details tucked up into the top right corner of the document.
You only need to include your name, telephone number, email address , and general location. Your CV profile or personal statement is a short simple paragraph that sits at the top of your CV, and summarises your abilities as a candidate.
The information you include in your CV will obviously differ depending on your profession and experience level, but generally speaking you should be giving a round-up of the following: Your industry experience — What types of companies have you worked for and how much industry experience do you have? Your professional skills — Are you sales person with talents in lead generation and relationship building?