{"id":20683,"date":"2018-12-04T08:30:21","date_gmt":"2018-12-04T16:30:21","guid":{"rendered":"https:\/\/blogs.msdn.microsoft.com\/dotnet\/?p=20405"},"modified":"2019-05-08T13:36:37","modified_gmt":"2019-05-08T20:36:37","slug":"announcing-entity-framework-core-2-2","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/dotnet\/announcing-entity-framework-core-2-2\/","title":{"rendered":"Announcing Entity Framework Core 2.2"},"content":{"rendered":"

Today we’re making the final version of EF Core 2.2 available, alongside ASP.NET Core 2.2<\/a> and .NET Core 2.2<\/a>. This is the latest release of our open-source and cross-platform object-database mapping technology.<\/p>\n

EF Core 2.2 RTM includes more than a hundred bug fixes and a few new features:<\/p>\n

Spatial data support<\/h2>\n

Spatial data can be used to represent the physical location and shape of objects. Many databases can natively store, index, and query spatial data. Common scenarios include querying for objects within a given distance, and testing if a polygon contains a given location. EF Core 2.2 now supports working with spatial data from various databases using types from the NetTopologySuite<\/a> (NTS) library.<\/p>\n

Spatial data support is implemented as a series of provider-specific extension packages. Each of these packages contributes mappings for NTS types and methods, and the corresponding spatial types and functions in the database. Such provider extensions are now available for SQL Server<\/a>, SQLite<\/a>, and PostgreSQL<\/a> (from the Npgsql project<\/a>). Spatial types can be used directly with the EF Core in-memory provider<\/a> without additional extensions.<\/p>\n

Once the provider extension is installed, you can enable it in your DbContext calling the UseNetTopologySuite method. For example, using SQL Server:<\/p>\n

public class MyDbContext : DbContext\r\n{\r\n    public DbSet Friends { get; set; }\r\n\r\n    protected override void OnConfiguring(DbContextOptionsBuilder options)\r\n    {\r\n        options.UseSqlServer(\r\n            \"Server=(localdb)\\\\mssqllocaldb;Database=SpatialFriends;ConnectRetryCount=0\",\r\n            b => b.UseNetTopologySuite());\r\n\r\n    }\r\n}<\/pre>\n
You can then start adding properties of supported types to your entities. For example:<\/p>\n
using NetTopologySuite.Geometries;\r\n\r\nnamespace MyApp\r\n{\r\n  public class Friend\r\n  {\r\n    [Key]\r\n    public string Name { get; set; }\r\n\r\n    [Required]\r\n    public Point Location { get; set; }\r\n  }\r\n}<\/pre>\n
You can then persist entities with spatial data:<\/p>\n
using (var context = new MyDbContext())\r\n{\r\n    context.Add(\r\n        new Friend\r\n        {\r\n            Name = \"Bill\",\r\n            Location = new Point(-122.34877, 47.6233355) {SRID = 4326 }\r\n        });\r\n    context.SaveChanges();\r\n}<\/pre>\n
And you can execute database queries based on spatial data and operations:<\/p>\n
  var nearestFriends =\r\n      (from f in context.Friends\r\n      orderby f.Location.Distance(myLocation) descending\r\n      select f).Take(5).ToList();<\/pre>\n
For more information on this feature, see the spatial data documentation<\/a>.<\/p>\n
Collections of owned entities<\/h2>\n
EF Core 2.0 added the ability to model ownership in one-to-one associations. EF Core 2.2 extends the ability to express ownership to one-to-many associations. Ownership helps constrain how entities are used.<\/p>\n
For example, owned entities: – Can only ever appear on navigation properties of other entity types. – Are automatically loaded, and can only be tracked by a DbContext alongside their owner.<\/p>\n
In relational databases, owned collections are mapped to separate tables from the owner, just like regular one-to-many associations. But in document-oriented databases, we plan to nest owned entities (in owned collections or references) within the same document as the owner.<\/p>\n
You can use the feature by calling the new OwnsMany() API:<\/p>\n
modelBuilder.Entity<Customer>().OwnsMany(c => c.Addresses);<\/pre>\n
For more information, see the updated owned entities documentation<\/a>.<\/p>\n
Query tags<\/h2>\n
This feature simplifies the correlation of LINQ queries in code with generated SQL queries captured in logs.<\/p>\n
To take advantage of query tags, you annotate a LINQ query using the new TagWith() method. Using the spatial query from a previous example:<\/p>\n
  var nearestFriends =\r\n      (from f in context.Friends.TagWith(@\"This is my spatial query!\")\r\n      orderby f.Location.Distance(myLocation) descending\r\n      select f).Take(5).ToList();<\/pre>\n
This LINQ query will produce the following SQL output:<\/p>\n
-- This is my spatial query!\r\n\r\nSELECT TOP(@__p_1) [f].[Name], [f].[Location]\r\nFROM [Friends] AS [f]\r\nORDER BY [f].[Location].STDistance(@__myLocation_0) DESC<\/pre>\n
For more information, see the query tags documentation<\/a>.<\/p>\n
Getting EF Core 2.2<\/h2>\n
The EF Core NuGet packages are available on the NuGet Gallery<\/a>, and also as part of ASP.NET Core 2.2<\/a> and the new .NET Core SDK<\/a>.<\/p>\n
If you want to use EF Core in an application based on ASP.NET Core, we recommend that first you upgrade your application to ASP.NET Core 2.2<\/a>.<\/p>\n
In general, the best way to use EF Core in an application is to install the corresponding NuGet package for the provider your application will use. For example, to add the 2.2 version of the SQL Server provider in a .NET Core project from the command line, use:<\/p>\n
$ dotnet add package Microsoft.EntityFrameworkCore.SqlServer -v 2.2.0<\/pre>\n
Or from the Package Manager Console in Visual Studio:<\/p>\n
PM> Install-Package Microsoft.EntityFrameworkCore.SqlServer -Version 2.2.0<\/pre>\n
For more information on how to add EF Core to your projects, see our documentation on Installing Entity Framework Core<\/a>.<\/p>\n
Compatibility with EF Core 2.1<\/h2>\n
We spent much time and effort making sure that EF Core 2.2 is backwards compatible with existing EF Core 2.1 providers, and that updating an application to build on EF Core 2.2 won’t cause compatibility issues. We expect most upgrades to be smooth, however if you find any unexpected issues, please report them to our issue tracker<\/a>.<\/p>\n
There is one known change in EF Core 2.2 that could require minor updates in application code. Read the description of the following issue for more details:<\/p>\n