Spring Boot 3 with H2 database example

    4.0.0
    
        org.springframework.boot
        spring-boot-starter-parent
        3.1.0
         
    
    com.example
    SpringBoot3H2
    0.0.1-SNAPSHOT
    SpringBoot3H2
    Demo project for Spring Boot
    
        17
    
    
        
            org.springframework.boot
            spring-boot-starter-data-jpa
        
        
            org.springframework.boot
            spring-boot-starter-web
        

        
            com.h2database
            h2
            runtime
        
        
            org.projectlombok
            lombok
            true
        
        
            org.springframework.boot
            spring-boot-starter-test
            test
        
    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
                
                    
                        
                            org.projectlombok
                            lombok
                        
                    
                
            
        
    

package com.example.demo.entity;

import jakarta.persistence.Entity;
import jakarta.persistence.GeneratedValue;
import jakarta.persistence.Id;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
@Entity
public class Product {

    @Id
    @GeneratedValue
    private Integer prodId;
    private String prodName;
    private double prodCost;
    public Product(String prodName, double prodCost) {
        super();
        this.prodName = prodName;
        this.prodCost = prodCost;
    }


}

package com.example.demo.repo;

import org.springframework.data.jpa.repository.JpaRepository;

import com.example.demo.entity.Product;

public interface ProductRepository extends JpaRepository{

}

package com.example.demo.runner;

import java.util.Optional;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.stereotype.Component;

import com.example.demo.entity.Product;
import com.example.demo.repo.ProductRepository;

@Component
public class TestRunner implements CommandLineRunner{

    @Autowired
    private ProductRepository repo;


    @Override
    public void run(String... args) throws Exception {

        Product p1 = new Product("P1",5600.4);
        Product p2 = new Product("P2",6600.4);
        Product p3 = new Product("P3",7600.4);

        //save product

        repo.save(p1);
        repo.save(p2);
        repo.save(p3);

        //find
        Optional opt = repo.findById(1);
        if(opt.isPresent()) {
            System.out.println(opt.get());
        }else {
            System.out.println("Not FOund");
        }

        //find all
        repo.findAll().forEach(System.out::println);

        //delete by id
        repo.deleteById(1);

        //delete all
        repo.deleteAll();
    }

}