How to Use deleteById in Spring Boot: Simple Guide

In Spring Boot, use deleteById(ID id) method from a repository interface that extends JpaRepository or CrudRepository to delete an entity by its ID. Simply call this method with the entity's ID, and Spring will remove the record from the database.

Syntax

The deleteById method is declared in Spring Data repository interfaces like JpaRepository or CrudRepository. It takes one parameter:

• id: The unique identifier of the entity to delete.

When called, it deletes the entity with the given ID from the database.

java

void deleteById(ID id);

Example

This example shows a Spring Boot repository deleting a user by their ID. The UserRepository extends JpaRepository, which provides deleteById. The UserService calls deleteById to remove a user.

java

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import jakarta.persistence.Entity;
import jakarta.persistence.Id;

@Entity
class User {
    @Id
    private Long id;
    private String name;

    // Constructors, getters, setters
    public User() {}
    public User(Long id, String name) {
        this.id = id;
        this.name = name;
    }
    public Long getId() { return id; }
    public void setId(Long id) { this.id = id; }
    public String getName() { return name; }
    public void setName(String name) { this.name = name; }
}

@Repository
interface UserRepository extends JpaRepository<User, Long> {}

@Service
class UserService {
    @Autowired
    private UserRepository userRepository;

    public void deleteUserById(Long id) {
        userRepository.deleteById(id);
    }
}

// Usage example (e.g., in a controller or test):
// userService.deleteUserById(1L);

Output

User with ID 1 is deleted from the database if it exists.

Common Pitfalls

Common mistakes when using deleteById include:

• Calling deleteById with an ID that does not exist causes EmptyResultDataAccessException.
• Not handling exceptions when the ID is missing.
• Assuming deleteById returns a value; it returns void.

To avoid errors, check if the entity exists before deleting or catch exceptions.

java

try {
    userRepository.deleteById(nonExistingId);
} catch (org.springframework.dao.EmptyResultDataAccessException e) {
    // Handle case when ID does not exist
}

// Or check existence first
if (userRepository.existsById(id)) {
    userRepository.deleteById(id);
}

Quick Reference

deleteById Cheat Sheet:

Method	Description
deleteById(ID id)	Deletes entity by ID, throws exception if ID not found
existsById(ID id)	Checks if entity exists by ID

Method	Description
deleteById(ID id)	Deletes entity by ID, throws exception if ID not found
existsById(ID id)	Checks if entity exists by ID

Key Takeaways

Use deleteById(ID id) from JpaRepository or CrudRepository to delete entities by ID.

deleteById throws an exception if the ID does not exist; handle or check existence first.

deleteById returns void and performs deletion directly in the database.

Always ensure the ID is valid and exists to avoid runtime exceptions.

Use existsById(ID id) to check presence before deleting if needed.