SQLiteModel | Easiest way to persist data in Swift | iOS library

Your forms action should be action="add" (you're missing the closing quotation to close the action)

This is a re-write of my original answer to address all the issues:

configure.swift

1. Don't define multiple instances of MigrationConfig() and DatabaseConfig().
2. Grouping related tasks (e.g. adding models) together will make your code easier to debug and maintain.
3. You have added two instances of .sqlite databases.
4. You omitted the . in .sqlite when you were adding the pizza model.

So, the relevant part of your configure.swift becomes:

The quick way of doing it is to do something like User.query(on: req).filter(\.email == email).count() and check that equals 0 before attempting the save.

However, whilst this will work fine for almost everyone, you still risk edge cases where two users try to register with the same username at the exact same time - the only way to handle this is to catch the save failure, check if it was because the unique constraint on the email and return the error to the user. However the chances of you actually hitting that are pretty rare, even for big apps.

What does your configuration for the SQLite database (typically in Sources/App/configure.swift) look like?

Is it actually persisting to disk, or just running an in-memory database (which goes away when you restart)?

You could use SwifQL lib for complex queries

I'm not sure that with SQLite it is possible to subquery Months, but with PostgreSQL it is really easy cause it supports JSON

So for PostgreSQL your query may look like

It seems like the table name generated by fluent is different than your db table name as Fluent generate the table with name same as the Model class name. In your case Post.

Add static property entity in your model class Post to define a custom table name.

like this:

If you want to access all reviews for the particular dish, try the following code.

tl;dr: We take a look at the Swift language reference, and sure enough, the usage of this backslash-dot notation is called a key-path-expression.

(The question has been sufficiently answered, by this point.)

A more hands-on approach on how to get to that piece of buried documentation:

As you can see from the code you posted, the User class contains a property named email.

Notice that, assuming you're using Xcode, if you replace return \.email with return \, you get the compile-error "Expected expression path in Swift key path", so this is a hint that this backslash-dot notation might have to do with something called a key path.

From that documentation on key-path, we see that we could also have written \User.email (and you can try it out in Xcode with no compiler error).

Understanding the greater context of what's going on in that code:

So, semantically, to understand the meaning of the usernameKey declaration you're looking at, we might want to understand what a WritableKeyPath is. In simple, from the documentation, we see that a WritableKeyPath is: "A key path that supports reading from and writing to the resulting value."

So, we see that the usernameKey declaration takes in a WritableKeyPath object and returns a String that is User.email.

Furthermore, it's apparent that the User class needs this usernameKey property in order to conform to the PasswordAuthenticatable protocol, which was imported on the first line with import Authentication (if you care to explore there, take a look at Dependencies > Auth 2.0.0 > Authentication > Basic > BasicAuthenticatable.swift).

Well you won't be able to do it quite like that, but you could write: