Skip to main content

EF Core - System.InvalidOperationException : The required column 'Id' was not present in the results of a 'FromSql' operation.

Yesterday I talked about an error I got when using the FromSql method in Entity Framework Core(EF Core). It allows you to execute raw SQL queries against a relational database. Here is the example I was using yesterday:

Remark: The FromSql method was introduced in EF Core 7.0. In older versions, you should use FromSqlInterpolated instead.

However when we tried to execute the code above it failed with the following error message:

System.InvalidOperationException : The required column 'Id' was not present in the results of a 'FromSql' operation.

You typically get the  error message above when there isn’t a matching column found in the SQL result for every property in your entity type.

In our case the query was using a ‘SELECT *’ so I couldn’t be that we missed a column. To explain what was causing the issue, I first have to show our entity type and mapping class:

As you can see there is a difference between the name of one of our columns(ProductID) and the property (Id). When you are using the LINQ syntax to query your data, EF Core will correctly translate between the two. However when you try to use the FromSql method, it will not use the mapping configuration and the returned column names should perfectly match with the property names.

To fix it, I updated the query to return an Id column:

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

Cache stampede: when our cache turned against us

While investigating some performance issues, we ran into an ASP.NET Core API that cached a fairly expensive aggregation query for 60 seconds. Under normal load, that was fine: one request rebuilds the cache, everyone else reads from it. Under peak load, dozens of requests would arrive in that same expiry window, all see a cache miss, and all fire the same expensive query in parallel. The database didn't like that. That was the moment when our caching layer stopped helping and started hurting. A burst of requests comes in at the same time, all miss the cache, and all go hammer the database or the downstream API at once. That's a cache stampede . The cache was supposed to protect our backend, and for a few hundred milliseconds it did the opposite. Why this happens IMemoryCache.GetOrCreate (and its async sibling) looks like it protects you, but it doesn't add any locking on its own. Look at the naive version: public async Task<Report> GetReportAsync(string key) ...
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