efcore | EF Core is a modern object-database mapper for .NET. It supports LINQ queries, change tracking, upda | Object-Relational Mapping library

 by   dotnet C# Version: v8.0.0-preview.5.23280.1 License: MIT

kandi X-RAY | efcore Summary

kandi X-RAY | efcore Summary

efcore is a C# library typically used in Utilities, Object-Relational Mapping applications. efcore has no bugs, it has no vulnerabilities, it has a Permissive License and it has medium support. You can download it from GitHub.

EF Core is a modern object-database mapper for .NET. It supports LINQ queries, change tracking, updates, and schema migrations.

            kandi-support Support

              efcore has a medium active ecosystem.
              It has 12547 star(s) with 2957 fork(s). There are 934 watchers for this library.
              It had no major release in the last 12 months.
              There are 1822 open issues and 17799 have been closed. On average issues are closed in 129 days. There are 27 open pull requests and 0 closed requests.
              It has a neutral sentiment in the developer community.
              The latest version of efcore is v8.0.0-preview.5.23280.1

            kandi-Quality Quality

              efcore has 0 bugs and 0 code smells.

            kandi-Security Security

              efcore has no vulnerabilities reported, and its dependent libraries have no vulnerabilities reported.
              efcore code analysis shows 0 unresolved vulnerabilities.
              There are 0 security hotspots that need review.

            kandi-License License

              efcore is licensed under the MIT License. This license is Permissive.
              Permissive licenses have the least restrictions, and you can use them in most projects.

            kandi-Reuse Reuse

              efcore releases are available to install and integrate.
              Installation instructions, examples and code snippets are available.
              It has 59 lines of code, 0 functions and 3801 files.
              It has low code complexity. Code complexity directly impacts maintainability of the code.

            Top functions reviewed by kandi - BETA

            kandi's functional review helps you automatically verify the functionalities of the libraries and avoid rework.
            Currently covering the most popular Java, JavaScript and Python libraries. See a Sample of efcore
            Get all kandi verified functions for this library.

            efcore Key Features

            No Key Features are available at this moment for efcore.

            efcore Examples and Code Snippets

            No Code Snippets are available at this moment for efcore.

            Community Discussions


            Inject IConfiguration to windows forms on .NET 6.0
            Asked 2022-Mar-21 at 21:38

            I have class library called Persistence.EFCore contains this method



            Answered 2022-Mar-21 at 21:38

            The first parameter of ConfigureService((context, services)=>{ ... }) is HostBuilderContext which gives you access to configuration, using its Configuration property.

            So assuming you have a service extension method which accepts configuration, then you can easily pass configuration to it using context.Configuration.


            Source https://stackoverflow.com/questions/71559139


            Ef Core Model Snapshot caching or is out of Sync
            Asked 2022-Mar-07 at 14:58

            I'm using efcore and I scaffolded from an existing database, but I forgot to make an initial migration when I did that so it picked up my new model. I decided that I wanted to keep them separate so I removed the migration, deleted the snapshot, and now every time I create another migration, it still has the new model in it.

            On top of this, using dotnet ef migrations list will list pending migrations that no longer exist. If I do dotnet ef database update they will get 'migrated` and show up in __MigrationHistory, but again, they don't actually exist in the directory.

            I've tried creating the files again, going as far as adding the class names to the files, doing a dotnet ef migrations remove, but I still have the same issue. It will delete the files, tell me everything is rolled back, but then the files will still be listed as pending, the database snapshot will still contain the new table (that doesn't exist) if I do any future migrations.

            Not really sure how to proceed. Everything I've read says that if I delete the snapshot and migrations, it will create a fresh snapshot, but it doesn't seem to do that. Is this stuff cached somewhere locally that I can clear out?



            Answered 2022-Mar-07 at 14:58

            Of course after posting this, I figured it out.

            My issue was that I kept running dotnet ef commands with the --no-build flag because they would fail. I know why they were failing, it wasn't a big deal, but apparently this prevented the snapshot from updating as well.

            So I fixed it by taking the offending files out of my folder for the moment, running dotnet ef migrations list, and with a successful build, it fixed all of the issues I was having.

            Source https://stackoverflow.com/questions/71382797


            An isolated transaction to (retrieve and delete) an entry from a table through Entity Framework Core?
            Asked 2022-Feb-28 at 04:49

            To visualize - naively - if I would like to complete such an operation, I would probably use the code below.

            Assume that dbContext and dbContext.Entries are of type DbContext (PostgreSQL) and DbSet respectively.



            Answered 2022-Feb-28 at 01:14

            If entity framework tries to modify or delete a record that is missing or had been recently updated, it will throw a DbUpdateConcurrencyException.

            DbUpdateConcurrencyException Exception thrown by DbContext when it was expected that SaveChanges for an entity would result in a database update but in fact no rows in the database were affected. This usually indicates that the database has been concurrently updated such that a concurrency token that was expected to match did not actually match

            Hence you could wrap your code in a try catch and catch that exception.

            Source https://stackoverflow.com/questions/71289496


            Cannot use NodaTime's Instant.InZone with the DateTimeZone in a variable with Npgsql's Entity Framework Core provider
            Asked 2022-Feb-25 at 21:53

            So I'm running into a rather odd issue here. I've got a PostgreSQL 14 server and I'm using the Npgsql Entity Framework Core provider to access it. If I have an Entity Framework Core entity that contains a date as a NodaTime Instant type (which becomes timestamp with time zone in the database) and try to project that via .InZone(timeZone).LocalDateTime, I run into 3 situations.

            Actual example query would be something like this:



            Answered 2022-Feb-25 at 21:53

            The NodaTime plugin doesn't support passing parameterized time zones from .NET; you can only use a constant expression such as DateTimeZoneProviders.Tzdb["Europe/Berlin"] (see these docs for supported translations). You can use this to convert a PG timestamp with time zone into a timestamp without time zone in PG, and then retrieve the result as a timestamp without time zone, which can be read as a NodaTime LocalDateTime.

            However, if what you're looking for is to get a ZonedDateTime/LocalDateTime with the time zone of the client machine (where .NET is executing), then doing .InUtc().LocalDateTime is the way to do that - any reason you're trying to avoid it?

            A bit more context (as well as a full code sample) could shed some more light on what you're trying to achieve.

            Source https://stackoverflow.com/questions/71271852


            Connecting to PostgreSql via Npgsql from ASP.NET Core 6 in a Docker Compose Stack
            Asked 2022-Feb-22 at 16:23

            I'm trying to create a docker-compose script to fire a stack with a PostgreSql database and an ASP.NET Core 6 Web API. To test the scenario, I've created a new ASP.NET Core 6 Web API using the default template. I have then added NuGet package Npgsql (6.0.3), and a sample controller which just queries the DB engine version, e.g.:



            Answered 2022-Feb-22 at 16:23

            When a container connects to another container on the bridge network, you use the container port. Not the mapped port on the host. So your connection string should be

            Source https://stackoverflow.com/questions/71224683


            Invalid column name when using EF Core filtered includes
            Asked 2022-Feb-13 at 21:05

            I came across this error when modifying a DB first project (using fluent migrator) and scaffolding the EF context to generate models. I have reproduced it by making a code-first simplification. This means that I can't accept answers that suggest modifying the annotations or fluent configuration, because this will be deleted and recreated on the next migration and scaffold.

            The simplified idea is that a device has:

            • many attributes
            • many histories representing changes to the device over time
              • each history entry has an optional location

            IOW you can move a device around to locations (or no location) and keep track of that over time.

            The code-first model I came up with to simulate this is as follows:



            Answered 2021-Nov-10 at 06:20

            Update: The bug is fixed in EF Core 6.0, so the next applies to EF Core 5.0 only.

            Looks like you have hit EF Core 5.0 query translation bug, so I would suggest to seek/report it to EF Core GitHub issue tracker.

            From what I can tell, it's caused by "pushing down" the root query as subquery because of the Take operator (which is basically what First method is using in the second case). This somehow messes up the generated subquery aliases and leads to invalid SQL.

            It can be seen by comparing the generated SQL for the first query

            Source https://stackoverflow.com/questions/69880136


            Seed owned type in EF Core 5
            Asked 2022-Feb-13 at 09:21

            I have the following configuration for which I want to provide some seed values.



            Answered 2022-Jan-01 at 16:42

            This is very similar to How to fix EF Core migration error on join table configuration, but for owned entity type.

            Be careful with fluent API overloads, as they return different things. For instance, OwnsOne without builder action delegate returns a builder for the owned entity type. But the overload with action returns the original (owner) entity builder so you can continue configuring it (the configuration of the owned entity is considered to be inside the action delegate).

            In your case, here

            Source https://stackoverflow.com/questions/70550087


            EF Core: Group By Failure - Translation of 'Select' which contains grouping parameter without composition is not supported
            Asked 2022-Feb-11 at 08:20

            The below LINQ query works perfectly fine in EF6 world where the whole query seems to be evaluated at the server (checked with SQL Profiler) but fails in EFCore6.



            Answered 2022-Feb-11 at 08:20

            Consider to rewrite your query until this bug is fixed

            Source https://stackoverflow.com/questions/71068747


            Configuring the IdentityModels navigation property with Guid for Entity Framework
            Asked 2022-Jan-24 at 15:49

            I get on creating Migration some Warnings like this one:

            The foreign key property 'AppUserClaim.UserId1' was created in shadow state because a conflicting property with the simple name 'UserId' exists in the entity type, but is either not mapped, is already used for another relationship, or is incompatible with the associated primary key type. See https://aka.ms/efcore-relationships for information on mapping relationships in EF Core.

            It applies to all entities with AppUser navigation property. Other navigation properties has no warning.



            Answered 2022-Jan-24 at 15:49

            I ran into a similar issue. In my OnModelCreating method, I had flipped the order in which I was applying migrations.

            Source https://stackoverflow.com/questions/70585888


            Upgraded my project to .net 6 now I have time zone in EF Core with postgreSQL
            Asked 2022-Jan-05 at 09:02

            I juste upgraded my web api to .net6 using EFCore and NPGSQL (Postgres). I had to Set a Switch for my code to work: AppContext.SetSwitch("Npgsql.EnableLegacyTimestampBehavior", true);

            Now EFCore Creates my DateTime fields to 'timestamp with time zone' which breaks everything.

            How can I get the old 'timestamp without time zone' for DateTime Types?

            Should I remove the LegacyTimestamp switch?

            Thanks for your help!



            Answered 2022-Jan-05 at 09:02

            I Fixed it by forcing column type for all DateTime and DateTime? to "timestamp without time zone" by adding the following code in the OnModelCreating of my DBContext.

            Source https://stackoverflow.com/questions/70085027

            Community Discussions, Code Snippets contain sources that include Stack Exchange Network


            No vulnerabilities reported

            Install efcore

            EF Core is available on NuGet. Install the provider package corresponding to your target database. See the list of providers in the docs for additional databases. Use the --version option to specify a preview version to install.
            Most people use EF Core by installing pre-build NuGet packages, as shown above. Alternately, the code can be built and packages can be created directly on your development machine.
            The latest stable version is available on NuGet. Use the --version option to specify a preview version to install.
            Most people use Microsoft.Data.Sqlite by installing pre-build NuGet packages, as shown above. Alternately, the code can be built and packages can be created directly on your development machine.


            We welcome community pull requests for bug fixes, enhancements, and documentation. See How to contribute for more information.
            Find more information at:

            Find, review, and download reusable Libraries, Code Snippets, Cloud APIs from over 650 million Knowledge Items

            Find more libraries

            Stay Updated

            Subscribe to our newsletter for trending solutions and developer bootcamps

            Agree to Sign up and Terms & Conditions

            Share this Page

            share link

            Reuse Pre-built Kits with efcore

            Consider Popular Object-Relational Mapping Libraries

            Try Top Libraries by dotnet


            by dotnetC#


            by dotnetC#


            by dotnetPowerShell


            by dotnetC#


            by dotnetC#