These are the domain classes that make up our model. Model classesįinally, a Blog and Post class have also been added to the project. This ensures that if the connection string is not present then Entity Framework will throw rather than creating a new database by convention. You should always use the name= syntax when you are using a connection string in the config file. Protected override void OnModelCreating(DbModelBuilder modelBuilder) public partial class BloggingContext : DbContext
EXISTING UNIVERSAL DATABASE MODELS CODE
This tells Code First that the connection string to use for this context should be loaded from the configuration file. You’ll also notice that the default constructor calls a base constructor using the name= syntax. The context exposes a DbSet for each type in our model. The context represents a session with the database, allowing us to query and save data. Derived ContextĪ BloggingContext class has been added to the project. Since we are mapping to an existing database these setting will be ignored in our application. You’ll notice some other settings in the configuration file too, these are default EF settings that tell Code First where to create databases. Configuration fileĪn App.config file has been added to the project, this file contains the connection string to the existing database. Once the reverse engineer process completes a number of items will have been added to the project, let's take a look at what's been added. Select the connection to the database you created in the first section and click NextĬlick the checkbox next to Tables to import all tables and click Finish Select Code First from Database and click Next This launches the Entity Data Model Wizard Select Data from the left menu and then ADO.NET Entity Data ModelĮnter BloggingContext as the name and click OK These tools are just generating code that you could also type by hand if you prefer. We will use the Entity Framework Tools for Visual Studio to help us generate some initial code to map to the database. Enter CodeFirstExistingDatabaseSample as the name.
EXISTING UNIVERSAL DATABASE MODELS WINDOWS
Select Windows from the left menu and Console Application.To keep things simple we will build a basic console application that uses Code First to do the data access: The new database will now appear in Server Explorer, right-click on it and select New QueryĬopy the following SQL into the new query, then right-click on the query and select ExecuteĬONSTRAINT PRIMARY KEY CLUSTERED ( ASC)ĬONSTRAINT PRIMARY KEY CLUSTERED ( ASC),ĬONSTRAINT FOREIGN KEY () REFERENCES. Select OK and you will be asked if you want to create a new database, select Yes If you haven’t connected to a database from Server Explorer before you’ll need to select Microsoft SQL Server as the data sourceĬonnect to your LocalDB instance, and enter Blogging as the database name Right click on Data Connections -> Add Connection… Let's go ahead and generate the database. Typically when you are targeting an existing database it will already be created, but for this walkthrough we need to create a database to access. See Get Entity Framework for information on installing the latest version of the Entity Framework Tools. You will also need version 6.1 (or later) of the Entity Framework Tools for Visual Studio installed.
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You will need to have Visual Studio 2012 or Visual Studio 2013 installed to complete this walkthrough. Optionally additional configuration can be performed using attributes on your classes and properties or by using a fluent API. Code First allows you to define your model using C# or VB.Net classes. This step-by-step walkthrough provides an introduction to Code First development targeting an existing database.