GraphQL APIs with Spring Boot · Pelajaran

Memperbarui dan Menghapus Data

Kembangkan mutasi untuk mengubah data yang ada dan menghapus catatan dari sistem Anda.

Memperbarui dan Menghapus Data adalah pelajaran GraphQL APIs with Spring Boot gratis di CoddyKit. Ini adalah pelajaran 3 dari 4. Kamu bisa membaca pelajaran lengkapnya di bawah secara gratis — lalu praktikkan langsung di browser dengan editor kode bawaan dan tutor AI 24/7. Ini adalah bagian dari jalur belajar GraphQL APIs with Spring Boot, dan progresmu tersinkronisasi di web dan aplikasi CoddyKit. Kursus GraphQL APIs with Spring Boot mencakup 4 pelajaran total.

Bagian dari pelajaran ini belum diterjemahkan dan ditampilkan dalam bahasa Inggris.

Changing Your Data

So far, you've learned to fetch data with queries and add new data with mutations. But what about modifying or removing existing records?

In this lesson, we'll dive into how GraphQL mutations allow you to update and delete data, making your applications fully dynamic.

GraphQL Update Mutation (SDL)

An update mutation modifies an existing record. It usually requires an identifier (like an ID) to specify which record to change, and then the fields you want to update.

Here's how you might define an updateBook mutation in your GraphQL schema (SDL):

type Mutation { updateBook(id: ID!, title: String, author: String, year: Int): Book }

Designing Update Input Types

For cleaner mutations, especially with many fields, it's good practice to use an Input Type. This bundles all arguments into a single object.

An Input Type is similar to a regular type but uses the input keyword.

input UpdateBookInput { id: ID! title: String author: String year: Int } type Mutation { updateBook(input: UpdateBookInput!): Book }

Spring Boot: Update Resolver

In your Spring Boot application, you'll create a Java method that acts as the resolver for the updateBook mutation.

This method will take the necessary arguments (like the book's ID and new details) and perform the update logic, often interacting with a database or service.

public Book updateBook(String id, String title, String author, Integer year) { // ... logic to find and update the book ... return updatedBook; }

Implementing Update Logic

Let's see a simple Java example of how an update might work. We'll use an in-memory list to simulate a data store.

Notice how we find the book by ID and then modify its properties.

public class Main {
  static class Book {
    String id;
    String title;
    public Book(String id, String title) {
      this.id = id;
      this.title = title;
    }
    public String getId() { return id; }
    public String getTitle() { return title; }
    public void setTitle(String title) { this.title = title; }
    @Override
    public String toString() { return "Book[id=" + id + ", title='" + title + "']"; }
  }

  private static java.util.List<Book> books = new java.util.ArrayList<>();

  public static void main(String[] args) {
    books.add(new Book("1", "Original Title"));
    books.add(new Book("2", "Another Book"));

    System.out.println("Before update:");
    books.forEach(System.out::println);

    // Simulate update logic
    String targetId = "1";
    String newTitle = "Updated Title";
    
    books.stream()
         .filter(b -> b.getId().equals(targetId))
         .findFirst()
         .ifPresent(book -> book.setTitle(newTitle));

    System.out.println("\nAfter update:");
    books.forEach(System.out::println);
  }
}

GraphQL Delete Mutation (SDL)

Deleting data is simpler. You typically only need to provide the unique ID of the record you wish to remove.

The delete mutation usually returns the ID of the deleted item, or a boolean indicating success.

type Mutation { deleteBook(id: ID!): ID }

Spring Boot: Delete Resolver

Similar to updating, a delete mutation in Spring Boot will have a corresponding Java method.

This method will receive the ID of the item to be deleted and perform the removal operation.

public String deleteBook(String id) { // ... logic to find and delete the book ... return id; }

Implementing Delete Logic

Here's a basic Java example of a delete operation. We'll remove a book from our in-memory list based on its ID.

The removeIf method is a concise way to delete elements that match a condition.

public class Main {
  static class Book {
    String id;
    String title;
    public Book(String id, String title) {
      this.id = id;
      this.title = title;
    }
    public String getId() { return id; }
    public String getTitle() { return title; }
    @Override
    public String toString() { return "Book[id=" + id + ", title='" + title + "']"; }
  }

  private static java.util.List<Book> books = new java.util.ArrayList<>();

  public static void main(String[] args) {
    books.add(new Book("1", "Book to Delete"));
    books.add(new Book("2", "Another Book"));

    System.out.println("Before delete:");
    books.forEach(System.out::println);

    // Simulate delete logic
    String targetId = "1";
    books.removeIf(book -> book.getId().equals(targetId));

    System.out.println("\nAfter delete:");
    books.forEach(System.out::println);
  }
}

Handling Missing Records

What happens if you try to update or delete a record that doesn't exist?

Your resolver should check if the ID exists.
If not found, it can return null or throw a specific GraphQL error (more on error handling in a later course!).
This prevents unexpected behavior and informs the client.

Quick Check: Mutation Operations

You've learned about different types of GraphQL operations. Let's test your understanding!

Recap: Mastered Data Changes!

Congratulations! You've learned how to implement powerful data modification features:

Update Mutations: Used to modify existing data records, identified by a unique ID.
Delete Mutations: Used to remove data records from your system, also identified by a unique ID.
Spring Boot Resolvers: How to map these mutations to Java methods for backend logic.

With queries, create, update, and delete mutations, you now have a full set of tools to build dynamic GraphQL APIs!

Pertanyaan yang Sering Diajukan

Apakah pelajaran “Memperbarui dan Menghapus Data” gratis?

Ya — teks lengkap “Memperbarui dan Menghapus Data” gratis dibaca di sini di web. Untuk praktiknya secara interaktif (editor kode bawaan dan tutor AI 24/7) dan buka sisa kursus GraphQL APIs with Spring Boot, upgrade ke CoddyKit PRO. Kursus GraphQL APIs with Spring Boot mencakup 4 pelajaran total.

Apa yang akan aku pelajari di “Memperbarui dan Menghapus Data”?

Kembangkan mutasi untuk mengubah data yang ada dan menghapus catatan dari sistem Anda. Kamu berlatih GraphQL APIs with Spring Boot dengan kode praktik yang langsung kamu jalankan di browser, dan tutor AI 24/7 menjawab pertanyaanmu saat kamu mengerjakan pelajaran ini.

Apakah aku perlu pengalaman untuk memulai GraphQL APIs with Spring Boot?

Tidak diperlukan pengalaman sebelumnya. GraphQL APIs with Spring Boot di CoddyKit dirancang untuk pemula hingga pelajar tingkat lanjut, jadi kamu bisa memulai di sini atau dari awal dan belajar sesuai kecepatan kamu sendiri. Ini adalah pelajaran 3 dari 4.

Berapa lama pelajaran “Memperbarui dan Menghapus Data” memakan waktu?

Sebagian besar pelajaran CoddyKit memakan waktu sekitar 5–10 menit. Setiap pelajaran ringkas dan interaktif, jadi kamu membuat kemajuan stabil dan melanjutkan dari tempat kamu tinggalkan di web dan aplikasi.

Bisakah aku menulis dan menjalankan kode dalam pelajaran GraphQL APIs with Spring Boot ini?

Ya. Setiap pelajaran GraphQL APIs with Spring Boot menyertakan editor kode bawaan, jadi kamu menulis dan menjalankan kode nyata langsung di browser dan mendapatkan umpan balik AI instan — tidak diperlukan penyiapan lokal.

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