Scaffold-DbContext 'Name=ConnectionStrings:Chinook' The following example scaffolds entity types and a DbContext from the Chinook database located on the machine's SQL Server LocalDB instance, making use of the database provider.ĭotnet ef dbcontext scaffold "Name=ConnectionStrings:Chinook" For example, PowerShell requires you to escape the $ character, but not \. ![]() How you quote and escape the connection string depends on which shell you are using to execute the command refer to your shell's documentation for more information. The tools will use this connection string to read the database schema. The first argument to the command is a connection string to the database. NET CLI commands have two required arguments: the connection string to the database, and the EF Core database provider to use. Install the NuGet package for the database provider that targets the database schema you want to scaffold from.īoth the PMC and the.Install the NuGet package for in the project you are scaffolding to.NET CLI tools, which across all platforms supported by. Before scaffolding, you'll need to install either the PMC tools, which work on Visual Studio only, or the.These tools provide a graphical tool which builds on top of the EF Core command line tools and offers additional workflow and customization options. I hope that you can either use the code as is or take some useful ideas out of it.If you use Visual Studio, try out the EF Core Power Tools community extension. Nevertheless, features such as support for custom database initializers and the ability to execute SQL statements from the DbContext provide really powerful extensibility capabilities. There are a lot of improvement opportunities for this implementation (such as adding support for clustered indexes). You could, for instance, have the IndexInitializer and another one to generate data. During the week I also put together a simple CompositeDatabaseInitializer that can be used to separate the logic in different initializers. Well, in this case, a simple approach would be to add the IndexInitializer logic to your own Initializer, but that is not the only way to support the IndexAttribute and keep your initialization logic. If, for example the Table and Column name are customized: For example, when using the following entity: I created a simple console application and ran a couple of tests to see if the data base was correctly created. It forces you to define the index name and gives the possibility of specifying whether the index is unique or not.Īnd the Initializer basically goes through the DbSet properties in the DbContext to retrieve the entity table names and check for the Index attribute in the properties in those entities. I found a couple of StackOverflow questions ( here and here) from where I got some really useful ideas, such as using the ExecuteSqlCommand method introduced in Entity Framework 4.1 and detecting the attributes in a DataBaseInitializer. By just looking at the entity you can determine the indexes that will be created for it, without the need to check a separate class' code. While developing your model changes a lot, so having to create an extra class whenever you discover that you want to add an index is not really confortable (once you have deployed to production however, migrations are probably the way to go). Code first migrations create a class per migration which results in too many classes.Update: After a quick twitter discussion with I decided to be more specific as to why I think using an attribute is better than code first migrations: Once I realized this, I decided to create the necessary components on my own. To my surprise, I wasn't able to find such an attribute when searching the web (for example, this is the list of available Data Annotations). ![]() Thus, I started to research to see if there where other ways to do this, thinking that there was probably an available data annotation to get this done. This approach successfully satisfied our requirements, but it required us to add additional migrations to specify the indexes. As we were also required to support changes to the model after the application was deployed, we decided to use Entity Framework Code Base Migrations. This week, for a project at Southworks, my friend Mariano Converti and I had to create indexes in a SQL database for two string type properties of entities that were part of an Entity Framework Code First model.
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