I’m using Entity Framework in most projects I’m working on – and for the most part, it’s a pleasure to work with. But as always, there are plenty of chances to run into issues – so obviously, I stumble into all of the rare stuff that IS broken! This one I hadn’t really seen before – “No database provider has been configured for this DbContext”. This time I encountered the issue while setting up a new project and getting started working on the model. EF…Continue reading Fixing “No database provider has been configured for this DbContext” in Entity Framework Core
Another quick one – I’m sure this doesn’t apply to all cases, but I’m still logging it in case someone (like myself) stumbles upon the issue and finds help here. I was building a solution with some Azure Functions fetching and populating data in a database, and was planning on building an UI for browsing the data at some point later on – but I actually got stuck on the second step already :) While adding the database to my project, while running Add-Migration in…Continue reading “An assembly specified in the application dependencies manifest was not found” when running Add-Migration in Entity Framework Core?
This article explains how to fix a weird situation where your .NET application utilizing Entity Framework or Entity Framework Core simply crashes without any way to recover or catch the Exception. You only get errors somewhere along the lines of “conversion overflow”. Ah – what a fun little issue! Problem So when you’re trying to instantiate an entity with a property of type decimal, you’ll get one of the 2 following exceptions with varying Call Stacks: Conversion overflow or: Arithmetic overflow error converting numeric to data type numeric…Continue reading “Conversion overflow” when reading numeric data from MS SQL database using Entity Framework
Hah – another interesting one. This article describes how to resolve an error along the lines of “Microsoft.Data.SqlClient: Microsoft.Data.SqlClient is not supported on this platform.“, thrown by Azure Functions host. Apparently you can run into this issue either on your local development machine or even in Azure. Problem For me, this error popped up after some house cleaning tasks – dependency updates, merging feature branches… You know the stuff. And suddenly, while the Azure Function App would build and run just fine, my SQL calls…Continue reading How to resolve “Microsoft.Data.SqlClient is not supported on this platform.” in an Azure Function App?
This article explains how to perform a very simple and lightweight database connection test for an existing database context. A while ago, I needed to develop a simple API that I can poll from a load balancer to see whether: An Azure service hosting it is up and It has a connection to its SQL database This simple API would be used for monitoring purposes – simple stuff, sure, but what’s the best way to implement this without causing any unnecessary load to the database,…Continue reading How to verify connection to database in Entity Framework Core?
This time, I’m happy to present you perhaps the simplest way of fixing an annoying and persistent issue with a misleading error message! Wait, does that sound familiar? It’s almost like that’s what half of my articles are about… Anyway, I was happily going my way about creating a couple of new fields to an entity and then scaffolding my changes to a new migration using Entity Framework Core’s Add-Migration, but this happened: Build started… Build failed. “Oh”, I thought. “I must have messed something…Continue reading How to resolve persistent “Build started… Build failed.” when trying to run Entity Framework Core commands?
This article offers yet another possible fix to an issue, where trying to call SaveChanges() in Entity Framework Core throws a pretty generic “An error occurred while updating the entries”-exception, and you’re left wondering what in tarnation is wrong this time. And admittedly, that’s a really generic error, so it could be pretty much whatever. But in this article, I’ll go through one possibility – hopefully it helps! Problem So I was just pushing in some new rows to an incredibly simple table in my…Continue reading How to resolve another “An error occurred while updating the entries” exception in Entity Framework Core
Recently, while building an app service to host a .NET Core API, I had to implement the logic for using both Read-Only and Read-Write Database Contexts for Entity Framework Core. In this particular case, it was the same database – just different contexts, because depending on the location of the app service the app was deployed in, read and write operations might actually go to different database instances, That’s really easy, right? Well… Yes and no. Essentially, it’s easy to spin up, but comes with…Continue reading How to implement multiple Connection Strings for one DbContext in EF Core?
This article describes how to access and extract the connection strings from your Entity Framework (Core) database context objects. This is quite convenient if you need to display or log the connection string used for your current DbContext for some reason – or if you somehow form your DbContext objects dynamically, and need to verify which connection string you’re using. I’m sure there are other use cases, too. You probably have an interesting one, if you landed on this page! Problem A while ago, I…Continue reading How to get the EF Core Connection String?
When you’re in your .NET Core project, it’s always easy: you just register your DbContext in ConfigureServices, and then inject it into whichever Page, View or Controller you might need it in. However, when you have another project or solution you’re working on and you’d still like to use the same DbContext and your entity classes in it, you have to find another way to do it! What should we do, then? Description Let’s first take a look at the use cases and tech stack.…Continue reading How to create a DbContext from just a connection string?
This is a tip that should often be the first thing you do in your projects with database backend, no matter which technology you use: Add some basic info about modified and created times, and the user information – so that if something happens, everyone will know who to blame 😉 There’s a lot of great blog articles describing how to do this in .NET Framework, but not that many for .NET Core. It’s very similar, but not the same. I learned that by copy-pasting…Continue reading How to add creator/modified info to all of your EF models at once in .NET Core
This article describes how to fix a situation, where you can’t use any of the navigation properties of your Entity Framework Core entities, since they are all null, despite data being in the database for sure. So, another day, another error. This time I can’t blame SharePoint, since I just messed up with ASP.NET Core and Entity Framework Core. :) Symptoms No matter what I’d do, I was getting null values for my navigation properties on my entities. They’d would always be null during runtime…Continue reading EF Core returns null for a Navigation property
This post describes how you can access your Entity Framework Core model classes and the database context in your Azure Functions. In my example I’m using EF Core 2.1, but the main principle should be the same for later versions as well. Please note, that I use Azure functions runtime v2 (but it should work the same in v3 !) Another easy one, that I was unable to find much guidance on! But first, let’s start with the basics. Why would you want to have…Continue reading How to access Entity Framework Core’s DbContext in an Azure Function?
Another weird, but simple issue I ran into when building a simple .NET Core application. The article should apply to pretty much any .NET Core version, but the version I was on was 2.2. I was just minding my own business, crafting since bits of code into something remotely functional, while I ran into an issue. While trying to apply my changes to the database using .NET Core Entity Framework, executing Update-Database simply failed with the following error: The EntityFramework package is not installed You…Continue reading EntityFramework Core – Update-Database error “The EntityFramework package is not installed”
This post describes one nobrainerish fix to the error “An assembly specified in the application dependencies manifest [projectname].deps.json was not found.” I ran into this while running Update-Database for my ASP.NET Core web project, that’s using EntityFrameworkCore 2.1.1. I hadn’t seen this one before, but the error was quite interesting: Error: An assembly specified in the application dependencies manifest (Koskila.[projectname].AzureFunctions.deps.json) was not found: package: ‘Koskila.[projectname].AzureFunctions’, version: ‘1.0.0’ path: ‘Koskila.[projectname].AzureFunctions.dll’ Well that’s a weird one coming from an update-database command! Posts Related to “Fixing “An assembly…Continue reading Fixing “An assembly specified in the application dependencies manifest [projectname].deps.json was not found”