What happens if the ID does not exist?

box.remove(id) returns false. No exception is thrown.

How do I delete multiple objects efficiently?

Use removeMany() or an equivalent bulk operation instead of calling remove() repeatedly.

How do I delete an object in ObjectBox?

Q: How do I delete an object in ObjectBox?

Use box.remove(id). If the object exists, it is deleted and the method returns true. If the object does not exist, it returns false.

Answer: Use box.remove(id).

If an object with that ID exists, it will be deleted and the method returns true.
If no object exists with that ID, it returns false.
For deleting multiple objects efficiently, use removeMany() or an equivalent bulk operation.

Purpose

The box.remove() method deletes a single object from the database based on its unique ID.
It is transactional and ensures that either the object is removed successfully or the operation has no effect.

Code Examples

Java
Kotlin
Swift
Dart
Python

Java example

Box<User> userBox = store.boxFor(User.class);
long userIdToDelete = 1;

boolean wasRemoved = userBox.remove(userIdToDelete);

if (wasRemoved) {
    System.out.println("Successfully removed user with ID " + userIdToDelete);
} else {
    System.out.println("Could not find user with ID " + userIdToDelete + " to remove.");
}

Kotlin example

val userBox = store.boxFor(User::class.java)
val userIdToDelete = 1L

val wasRemoved = userBox.remove(userIdToDelete)

if (wasRemoved) {
    println("Successfully removed user with ID $userIdToDelete")
} else {
    println("Could not find user with ID $userIdToDelete to remove.")
}

Swift example

do {
    let userBox = store.box(for: User.self)
    let userIdToDelete: Id<User> = 1

    let wasRemoved = try userBox.remove(userIdToDelete)
    
    if wasRemoved {
        print("Successfully removed user with ID \(userIdToDelete)")
    } else {
        print("Could not find user with ID \(userIdToDelete) to remove.")
    }
} catch {
    print("An error occurred: \(error)")
}

Dart example

final userBox = store.box<User>();
final userIdToDelete = 1;

final wasRemoved = userBox.remove(userIdToDelete);

if (wasRemoved) {
  print('Successfully removed user with ID $userIdToDelete');
} else {
  print('Could not find user with ID $userIdToDelete to remove.');
}

Python example

user_box = store.box(User)
user_id_to_delete = 1

was_removed = user_box.remove(user_id_to_delete)

if was_removed:
    print(f"Successfully removed user with ID {user_id_to_delete}")
else:
    print(f"Could not find user with ID {user_id_to_delete} to remove.")

Edge Cases & Pitfalls

Non-existent ID: Returns false (does not throw an exception).
Invalid ID (0 or negative): Treated as non-existent, returns false.
Bulk deletes: Use removeMany() for performance when removing multiple IDs.
Remove by object reference: Some bindings allow remove(object) in addition to remove(id).
Transactions: Removing multiple objects can be wrapped in a single transaction for atomicity.

Purpose​

Code Examples​