We’ll see how this works as we get into defining our classes.īefore diving into C# code, let’s discuss our topic. Typically, our classes will map one to one with our database tables, and relationships between tables are defined using navigational conventions. To get started using EF Core 5, we need to define a class that derives from DbContext and contains our models. What is DbContext? The DbContext is a specialized base class that tracks our in-memory operations, allowing us to write and execute queries, track changes that we can persist back to our database, and interact with our database engine indirectly or directly in exceptional circumstances. Code-first modelingĮvery EF Core solution will have at least one DbContext implementation. Great! We’re now ready to start modeling our problem domain.įolks who want to follow along can clone a sample project from GitHub. When we finish setting up our project, we can run the dotnet-ef command, where the EF unicorn will greet us. From within the newly created project directory type the following commands into Rider’s integrated terminal. We can use the NuGet tool window to find and install all these packages into our project.Īdditionally, we will want to install the dotnet-ef command-line tool (CLI). Starting with a brand new console application, we will need to install the following packages, making sure that all the versions are 5.0.0: NET Core 3.1, but aligning versions is always a good idea. To get started, I recommend folks install the latest version of the. We’ll design a schema for entertainment productions using a code-first approach, migrate an SQLite database to our schema’s current incarnation, seed our database, and run some typical LINQ queries. In this post, we’ll see how we can get started with EF Core 5. Conceived initially as a designer-centric tool heavily reliant on Visual Studio’s graphical user interface and SQL Server, EF’s current philosophy recognizes the need to be friendlier to ideas like distributed source-control, build servers, multiple database engines, and operating systems. For those unfamiliar with the technology, Entity Framework is an object-relational mapper (ORM), helping developers overcome the impedance mismatches between C# and a database instance’s schema.Įntity Framework has come a long way since its original inception. Let’s say a few things have changed since the initial release. NET community got its first glimpse of Entity Framework (EF) on August 11th, 2008, with the release of. NET 5 release comes the newest Entity Framework Core version, unsurprisingly called Entity Framework Core 5 (EF Core 5). This cmdlet supports the common parameters: Verbose, Debug,ĮrrorAction, ErrorVariable, WarningAction, WarningVariable, Specifies the provider invariant name of the connection string. Specifies the the connection string to use. Specifies the name of a connection string to use from the application’s If omitted, migrations willĪttempt to locate a single migrations configuration type in the target Specifies the migrations configuration to use. Omitted, the specified project’s configuration file is used. Specifies the configuration file to use for named connection strings. If omitted, the default project selected in package manager console Specifies the project that contains the migration configuration type to be Specifies that data loss is acceptable during automatic migration of the Generate a SQL script rather than executing the pending changes directly. Specifies the name of a particular migration to update the database to. If omitted, the last applied migration in Specifies the name of a particular migration to useĪs the update’s starting point. Updates the database to the current model by applying pending migrations. ProjectName ] -ConnectionString -ConnectionProviderName )Īpplies any pending migrations to the database. (Note, I just had to correct the misspelling of omitted when I pasted this in. I show that output below the output of the DETAILED display. –full provides the description and then even more detail about how to use each parameter.-detailed gives a description of each parameter.I don’t know how to get the “full” information from the command line but it’s available in the Package Mgr Console and displayed below. Or if you are using the command line just type migrate –? as you can see in this blog post I wrote about executing migrations from the command line. You can get at the details from the Package Manager Console in Visual Studio with the get-help commandlet as shown below. These can also be used if you want to execute the migrations from the command line using the counterpart migrate.exe command rather than from within Visual Studio. In my recent Code First Migrations course on, I showed how you can get detailed information about the parameters of update-database.
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