On Friday I attended Microsoft’s ‘Insider Dev Tour’ in Melbourne, one of about 44 similar events being held around the world throughout the month of June. Microsoft advertised the event as being ‘for developers interested in building Microsoft 365 experiences (…) today, using the latest dev technologies, as well as for those who want a peek into the future,’ and it was completely free to attend. Hosted at the offices of Xello, a Melbourne-based IT consultancy company, the event was all day, running from the hours of 8 to 5, and had food and coffee provided.
I was fairly excited when I heard about the event, having being recently drawn in to the Windows desktop development ecosystem through my involvement in the Open Live Writer project. I wasn’t going in with any particular agenda on things I would’ve liked to learn, but rather I was just curious as to how the whole day would play out and if I’d pick up any nifty skills. I’ve never been to any kind of developer conference before, so really this would’ve been a first for me.
A recent uni assignment has required me to implement an ASP.NET Core REST API using EntityFrameworkCore on a pre-existing database. Whilst EF Core tends to generate controllers for models with single primary keys just fine, I’ve found that it has no support for composite primary keys. This requires you to alter your controller classes to add the support manually, which in my case involved the following;
- Alter the paths of the individual Get, Put, and Delete endpoints to contain two (or more, depending on how many keys are in your composite) parameters, and then alter the method parameters to match. This requires careful consideration as there are many different ways you can structure the parameters in your route.
- Alter every usage of _context.nameOfModelHere.FindAsync to contain all components of your primary key. Look at the model’s Entity definition in your database context class, specifically the usage of entity.HasKey, to determine the order in which to list the components in your key to FindAsync.
- Alter the nameOfModelHereExists method to take the correct amount of parameters for your key. Adjust the body of the method accordingly to check all parts of the key; I just added && at the end of the existing equality expression, and added more equality expressions.
- Alter all usages of nameOfModelHereExists appropriately.
- In the Put method, alter the second if statement to check all the components of your primary key, rather than just id.
- In the Post method, adjust the CreatedAtAction call in the return statement to contain all the components of your primary key.
- I would also recommend updating all the auto-generated comments that EntityFramework put in to keep things consistent.