Reading Time: 2 minutes. This post describes the fix to error “No Entity Framework provider found for the ADO.NET provider with invariant name ‘System.Data.SqlClient’“, which Visual Studio throws at your face when you try to run an application on any Windows-based system (or which you’ve dug out of event logs). Also, your application is probably built on .NET Framework and Entity Framework. Let’s get into it! Error When debugging/running your code you get an error like this: An exception of type ‘System.InvalidOperationException’ occurred in EntityFramework.dll but was not handled in […]
Tag: EF
Applying Entity Framework’s Code-First Migrations against a Database in Azure by running Update-Database
Reading Time: 3 minutes. This post describes how to run Entity Framework’s code-first migrations against a database located in the Windows Azure. This is done by running Update-Database commandlet with suitable switches, see below. The problem and symptoms Okay, so you’re developing your MVC+EF cool web app with a database in Azure, and you’re using code-first migrations. Cool! What’s nice with code-first-migrations is the fact they are run automatically even in the cloud the next time your app is running (as long as you publish your app with that […]
Solving the “Spatial types and functions are not available …” -problem
Reading Time: 3 minutes. This page describes mutiple ways on how to fix the exception ‘Spatial types and functions are not available for this provider because the assembly ‘Microsoft.SqlServer.Types’ version 10 or higher could not be found.‘ which comes up during debugging or publishing your program, app or service using DbGeography. Symptoms While running a console program or perhaps installing an ASP.NET MVC website on a machine, where SQL Server (apart from the one that comes with the Visual Studio) has not been installed, you may encounter the following error: […]
Fixing the error: “Column XX in table dbo.YY is of a type that is invalid for use as a key column in an index.”
Reading Time: 2 minutes. While using Entity Framework and code-first migrations, Entity Framework (EF) creates the indexes for you – but what if you need to create a custom one, explicitly based on certain field / column? Then you’ll have to tell EF which one to use as a key column. Usually, it’s easy – you just add the following annotation to the columns you’ll be using: [Index(“OfficialIds”, 1)] public int AreaId { get; set; } [Index(“OfficialIds”, 2)] public string EstateId { get; set; } (example stripped of extra code and other columns for clarity) And after adding the migration (Add-Migration… commandlet) you get […]
Fixing “An error occurred while updating the entries” while running code-first migrations in MVC 5 app
Reading Time: 5 minutes. This post describes an issue with EF’s code-first migrations, when mapping between DB’s DateTime (datetime2) and C#’s DateTime kind of fails, and results in Update-Database cmdlet failing. It’s more or less a prime example of a situation, where the error itself tells very little about the actual issue, and since debugging code-first migrations is kind of difficult (see the best tips for that here!), it’s cumbersome to investigate. Symptoms An exception of type ‘System.Data.Entity.Infrastructure.DbUpdateException’ occurred in EntityFramework.dll but was not handled in user code. I’ve […]