Entity Framework Blog - Posts on EF performance, new features etc.- Page 3 of 3

Fix the ‘Unable to resolve service for type Microsoft EntityFrameworkCore DbContext’ error after scaffolding an MVC Controller in Visual Studio

If you’ve got this error after scaffolding a controller which uses Entity Framework Core like below… it means you haven’t … Continue reading Fix the ‘Unable to resolve service for type Microsoft EntityFrameworkCore DbContext’ error after scaffolding an MVC Controller in Visual Studio

Customizing SQL Server column types when using Entity Framework Core code first

In Entity Framework when we’re using the code first approach EF will examine our classes and using a defined mapping … Continue reading Customizing SQL Server column types when using Entity Framework Core code first

Using Dependency Injection with Entity Framework DbContext in .NET MVC apps

When using Entity Framework Core and ASP.NET Core MVC we can easily inject a DbContext instance into our controller, repository … Continue reading Using Dependency Injection with Entity Framework DbContext in .NET MVC apps

Labelling Entity Framework Core queries in log files using TagWith

In Entity Framework Core (2.2+) if you’re capturing queries in logs consider using the TagWith feature to output an arbitrary … Continue reading Labelling Entity Framework Core queries in log files using TagWith

Using split queries (AsSplitQuery) in Entity Framework Core to avoid the cartesian explosion problem

Without lazy loading in Entity Framework Core we must eagerly load related entities which means we can experience the ‘cartesian … Continue reading Using split queries (AsSplitQuery) in Entity Framework Core to avoid the cartesian explosion problem

String.FirstOrDefault() LINQ queries now supported in Entity Framework Core 5.0

Entity Framework Core 5.0 now supports the translation of String.FirstOrDefault() LINQ queries. In EF Core 3.1 the following would fail… … Continue reading String.FirstOrDefault() LINQ queries now supported in Entity Framework Core 5.0

Suppress output of OnConfiguring method in Entity Framework Core 5.0

If you’re using Entity Framework Core with the database first approach and re-scaffold you’ll see that by default EF Core … Continue reading Suppress output of OnConfiguring method in Entity Framework Core 5.0

AsNoTracking with identity resolution now available in Entity Framework Core 5.0

AsNoTracking() has been around in Entity Framework for a while. Its ideal to use when pulling back a collection of … Continue reading AsNoTracking with identity resolution now available in Entity Framework Core 5.0

Does using the repository pattern with Entity Framework make sense?

I really enjoyed the Entity Framework Community Standup Ask Me Anything with Julie Lerman the other night (10th March 2021)… … Continue reading Does using the repository pattern with Entity Framework make sense?

How to select specific columns in Entity Framework Core

When writing SQL queries we should avoid SELECT * if we don’t need all columns as it can have a … Continue reading How to select specific columns in Entity Framework Core

Filtered includes now supported in Entity Framework Core 5.0

Filtered includes is an awesome new feature in Entity Framework Core 5.0 which was released in November 2020. Without lazy … Continue reading Filtered includes now supported in Entity Framework Core 5.0

Reading Entity Framework Core connection string from appSettings.json

When you run Scoffold-DbCotext with a connection string EF Core will scaffold your DB but will put the hardcoded connection string … Continue reading Reading Entity Framework Core connection string from appSettings.json

Setting batch size in Entity Framework Core

Entity Framework (pre-core) didn’t support batching of CUD statements, so if you were inserting 100 entities for example, EF sent … Continue reading Setting batch size in Entity Framework Core

View SQL queries run by Entity Framework Core in the console

In Entity Framework Core writing the executed queries to the console is easy. Just create a ILoggerFactory and then configure … Continue reading View SQL queries run by Entity Framework Core in the console

Make entities inherit from a base class in Entity Framework Core DB First

It’s often useful to have our entities inherit from a base class. This is easily done using EF Core Power … Continue reading Make entities inherit from a base class in Entity Framework Core DB First

Excluding tables in Entity Framework Core Scaffold-DbContext command

In Entity Framework Core DB First if you don’t want models created for certain tables you need to explicitly list … Continue reading Excluding tables in Entity Framework Core Scaffold-DbContext command

Setting Global Query Filters on multiple entities dynamically in Entity Framework Core

Since Entity Framework Core 2 we can use Global Query Filters to add where clauses to any queries EF generates … Continue reading Setting Global Query Filters on multiple entities dynamically in Entity Framework Core

Using Entity Framework Core Interceptors to log SQL queries

Since version 3 Entity Framework Core has supported Interceptors. The interception API allows developers to easily intercept and examine and … Continue reading Using Entity Framework Core Interceptors to log SQL queries

Run Scaffold DBContext without overwriting custom code in Entity Framework core.

I prefer to use DB first approach with Entity framework as many do. In this scenario when the underlying DB … Continue reading Run Scaffold DBContext without overwriting custom code in Entity Framework core.

Generating sequential GUIDs which sort correctly in SQL Server in .net

Using a non sequential GUID in either a clustered or non clustered index is not ideal from a performance point … Continue reading Generating sequential GUIDs which sort correctly in SQL Server in .net

Viewing SQL generated by Entity Framework when querying or calling SaveChanges()

When using Entity Framework, in an effort to track down bugs or performance problems, it’s very handy to see what … Continue reading Viewing SQL generated by Entity Framework when querying or calling SaveChanges()

Validation failed for one or more entities. See ‘EntityValidationErrors’ property for more details

You may see this exception when doing a DbContext.SaveChanges() call. You then may go drilling into the exception details to … Continue reading Validation failed for one or more entities. See ‘EntityValidationErrors’ property for more details

Passing userId to SQL Server delete trigger from entity framework

If you’re in an enterprise environment some form of auditing is likely to be required so you can track who … Continue reading Passing userId to SQL Server delete trigger from entity framework

Improving performance of read only selects in entity framework by turning off tracking with AsNoTracking method

We had a new contractor start the other day in work and he brought to my attention the ability to … Continue reading Improving performance of read only selects in entity framework by turning off tracking with AsNoTracking method

Using Optimistic concurrency with Entity Framework over SQL Server

If you want to have a client-wins or last in wins approach to concurrency management you don’t have to do anything, … Continue reading Using Optimistic concurrency with Entity Framework over SQL Server