Creating, Updating, and Deleting Records with Fluent

Episode #358 | 19 minutes | published on October 4, 2018 | Uses Xcode-10.0, Vapor-3.0.8, FluentSQLite-3.0.0, swift-4.2
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Now that we have Fluent set up, let’s see how we can use it to add, update, and delete records to the database. We’ll get a taste for how futures work in Vapor, and we will also see some of the builtin features that Vapor has to make loading records from your routes really simple.

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Create a route to save a record

In the routes file:

router.get("_demo") { req -> Future<String> in 
    let post = Post(title: "Hello Fluent", body: "This is how you set up a database using Vapor Fluent", author: "Ben")
    post.publishedAt = Date()

    return post.save(on: req).map { post in 
        return "Created post with ID: \(post.id!)"
    }
}

Deleting a record

We'll first see the hard way of doing it (because that's a great way to learn the magic behind Vapor) and then we'll look at an easier way.

router.delete("posts", Int.parameter) { req -> Future<String> in 

    let postId = try req.parameters.next(Int.self)
    return Post.find(postId, on: req).flatMap { maybePost in

        guard let post = maybePost else {
            throw Abort(.notFound)
        }

        return post.delete(on: req).map {
            return "deleted post: \(post.id!)"
        }
    }   
}

As it turns out, fetching a record and performing an action on it is a really common operation, so Fluent has a great feature for making this easier.

Automatically fetching records as route parameters

Let's open up our Post.swift file and add this at the bottom:

extension Post : Parameter {}

We can then alter the route above like this:

router.delete("posts", Post.parameter) { req -> Future<String> in
    guard let futurePost = try? req.parameters.next(Post.self) else {
        throw Abort(.badRequest)
    }

    return futurePost.flatMap { post in
        return post.delete(on: req).map {
            return "deleted post: \(post.id!)"
        }
    }
}

This is a huge time saver and shows off the power of Vapor's integration with Fluent.

Updating Records

Let's finish up our example by creating a route that will publish a post. In this example I want to return the JSON of the post we are modifying.

Let's go back to Post.swift and add this at the bottom:

extension Post : Content {}

This tells Vapor that our model can be serialized. This uses Codable to return JSON representations of our models.

Now we can tell our route to simply return a Post (in the future).

// PUT /posts/1/publish
router.put("posts", Post.parameter, "publish") { req -> Future<Post> in

    try req.parameters.next(Post.self).flatMap { post in
        post.publishedAt = Date()
        return post.save(on: req)
    }
}

As you can see, once you get used to the Future syntax, manipulating records is fairly straightforward.

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