SpringBoot访问MongoDB数据库的两种方式

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-mongodb</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
</dependency>

@Data
@AllArgsConstructor
@Document("User") //指定了这个模型类型所对应的集合名称即collection 表名
public class User {
    @Id //自动生成的主键ID 主键 不可重复 自带索引
    private String id;
    private String name;
    private Integer age;
}

@SpringBootTest
public class MongoTemplateTest {
    @Autowired
    private MongoTemplate mongoTemplate;
    @Test
    public void testMongoDB(){
        //向表中插入数据
        User user = new User(null,"张三",20);
        User user1 = new User(null,"李四",16);
        mongoTemplate.insert(user);
        mongoTemplate.insert(user1);
        //查询表中所有记录
        List<User> userList = mongoTemplate.findAll(User.class);
        System.out.println(userList);
        //[User(id=63acf541e6af652ac74fd008, name=张三, age=20),
        // User(id=63acf541e6af652ac74fd009, name=李四, age=16)]
        //根据表中id查询记录
        User user2 = mongoTemplate.findById("63acf541e6af652ac74fd008", User.class);
        System.out.println(user2);//User(id=63acf541e6af652ac74fd008, name=张三, age=20)
        //条件查询
        Query query = new Query(Criteria.where("name").is("李四").and("age").is(16));
        List<User> users = mongoTemplate.find(query, User.class);
        System.out.println(users);//[User(id=63acf541e6af652ac74fd009, name=李四, age=16)]
        //根据_id删除表中记录
        Query query2 = new Query(Criteria.where("_id").is("63acf541e6af652ac74fd008"));
        DeleteResult remove = mongoTemplate.remove(query2, User.class);
        //获取删除记录的个数
        long count = remove.getDeletedCount();
        System.out.println(count);//1
        //删除表中所有数据
        Query query3 = new Query();
        mongoTemplate.remove(query3,User.class);
    }
}

public interface UserRepository extends MongoRepository<User,String> {
}

@SpringBootTest
public class MongoRepositoryTest {
    @Autowired
    private UserRepository userRepository;
    @Test
    public void test(){
        //向数据库表中插入数据
        User user = new User(null,"张三三",18);
        User user1 = new User(null,"李四",16);
        userRepository.save(user);
        userRepository.save(user1);
        //查询数据库表中所有记录
        List<User> all = userRepository.findAll();
        System.out.println(all);
        //[User(id=63acf24938e0d1033d50dc20, name=张三三, age=18),
        // User(id=63acf24938e0d1033d50dc21, name=李四, age=16)]
        //按照id查询表中数据
        User user2 = userRepository.findById("63acf24938e0d1033d50dc20").get();
        System.out.println(user2);//User(id=63acf24938e0d1033d50dc20, name=张三三, age=18)
        //按条件(姓名与年龄)查询
        Example<User> example = Example.of(new User(null,"李四",16));
        List<User> list = userRepository.findAll(example);
        System.out.println(list);//User(id=63acf24938e0d1033d50dc21, name=李四, age=16)
        //模糊查询
        User user3 = new User(null,"三",18);
        //模糊查询匹配规则
        ExampleMatcher matcher = ExampleMatcher.matching()
                .withStringMatcher(ExampleMatcher.StringMatcher.CONTAINING)
                .withIgnoreCase(true);//忽略大小写
        Example<User> example1 = Example.of(user3,matcher);
        List<User> list1 = userRepository.findAll(example1);
        System.out.println(list1);//User(id=63acf24938e0d1033d50dc20, name=张三三, age=18)
        //分页查询
        Pageable pageable = PageRequest.of(0, 2);//设置分页参数：第1页 每页2条数据
        Page<User> page = userRepository.findAll(pageable);
        System.out.println("Page的总页数是：" + page.getTotalPages() + ",Page的总记录条数是：" + page.getTotalElements());
        //Page的总页数是：1 + ,Page的总记录条数是：2
        //根据_id修改信息
        User user4 = userRepository.findById("63acf24938e0d1033d50dc20").get();
        user4.setName("王五");//将取出的信息修改其name
        userRepository.save(user4);
        //根据id删除
        userRepository.deleteById("63acf24938e0d1033d50dc20");
        //删除全部
        userRepository.deleteAll();
    }
}