Skip to main content

EF Core - Error CS1503 Argument 2: cannot convert from 'string' to 'System.FormattableString'

I was pair programming with a team member when she got the following compiler error:

Error CS1503 Argument 2: cannot convert from 'string' to 'System.FormattableString'

The error appeared after trying to compile the following code:

The reason becomes apparent when we look at the signature of the SqlQuery method:

As you can see the method expects a FormattableString not a string. Why is this?

By using a FormattableString EF Core can protect us from SQL injection attacks. When we use this query with parameters(through string interpolation), the supplied parameters values are wrapped in a DbParameter.

To get rid of the compiler error, we can do 2 things:

1. We explicitly create  a FormattableString from a regular string:

2. We use string interpolation and add a ‘$’ sign in front of the query string:

More information

SQL Queries - EF Core | Microsoft Learn

RelationalDatabaseFacadeExtensions.SqlQuery<TResult> Method (Microsoft.EntityFrameworkCore) | Microsoft Learn

Labels:

Popular posts from this blog

Podman– Command execution failed with exit code 125

After updating WSL on one of the developer machines, Podman failed to work. When we took a look through Podman Desktop, we noticed that Podman had stopped running and returned the following error message: Error: Command execution failed with exit code 125 Here are the steps we tried to fix the issue: We started by running podman info to get some extra details on what could be wrong: >podman info OS: windows/amd64 provider: wsl version: 5.3.1 Cannot connect to Podman. Please verify your connection to the Linux system using `podman system connection list`, or try `podman machine init` and `podman machine start` to manage a new Linux VM Error: unable to connect to Podman socket: failed to connect: dial tcp 127.0.0.1:2655: connectex: No connection could be made because the target machine actively refused it. That makes sense as the podman VM was not running. Let’s check the VM: >podman machine list NAME         ...
Read more

Azure DevOps/ GitHub emoji

I’m really bad at remembering emoji’s. So here is cheat sheet with all emoji’s that can be used in tools that support the github emoji markdown markup: All credits go to rcaviers who created this list.
Read more

Cleaner switch expressions with pattern matching in C#

Ever find yourself mapping multiple string values to the same result? Being a C# developer for a long time, I sometimes forget that the C# has evolved so I still dare to chain case labels or reach for a dictionary. Of course with pattern matching this is no longer necessary. With pattern matching, you can express things inline, declaratively, and with zero repetition. A small example I was working on a small script that should invoke different actions depending on the environment. As our developers were using different variations for the same environment e.g.  "tst" alongside "test" , "prd" alongside "prod" .  We asked to streamline this a long time ago, but as these things happen, we still see variations in the wild. This brought me to the following code that is a perfect example for pattern matching: The or keyword here is a logical pattern combinator , not a boolean operator. It matches if either of the specified pattern...
Read more