# Mango DB
# 实际项目应用
- 操作日志（转账记录、权限变动的日志）
- 电商产品详情页的评论信息和商品规格参数（参数数量多，不同的商品参数字段变化很大）
# 使用场景
- 社交产品：用户信息、朋友圈信息
- 视频直播：用户信息、评论
- 物流场景：存储订单状态
# 与Spring Boot 整合
# 1.pom依赖
# version 用的是父模块的version，跟springboot版本号相同，当前是2.7.7
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<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>
</dependencies>
# 2.yml配置
spring:
data:
mongodb:
uri: mongodb://localhost:27017/demo
# uri: mongodb://账号:密码@ip:端口/数据库名
field-naming-strategy: org.springframework.data.mapping.model.SnakeCaseFieldNamingStrategy # 自动转驼峰
# 3.实体类和mongo注解
package org.example.mongodb.entity;
import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.Document;
import org.springframework.data.mongodb.core.mapping.Field;
import java.util.Date;
@Document("good_info") //表示当前文档属于哪个集合-表名
@Data
@ToString
public class User {
@Id //当前类的 id 映射文档中的 _id
private Integer id;
private String name;
private Integer age;
@Field("work_day") //当前类的 workDay 映射文档中的 work_day
private Date workDay;
}
# 4.测试类
package org.example.mongodb;
import com.mongodb.client.MongoCollection;
import org.bson.Document;
import org.example.mongodb.entity.User;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.domain.Sort;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.query.BasicQuery;
import org.springframework.data.mongodb.core.query.Criteria;
import org.springframework.data.mongodb.core.query.Query;
import java.util.Date;
import java.util.List;
@SpringBootTest
public class BaseTest {
@Autowired
private MongoTemplate mongoTemplate;
/**
* 创建集合（表），默认数据库demo
*/
@Test
void createCollection(){
if(!mongoTemplate.collectionExists("good_info")) {
//不存在才能创建，如果以及存在再创建就会报错
mongoTemplate.createCollection("good_info");
}
}
/**
* 查询集合
*/
@Test
void queryCollection(){
MongoCollection<Document> goodInfo = mongoTemplate.getCollection("good_info");
System.out.println(goodInfo.getNamespace());
}
/**
* 删除集合
*/
@Test
void removeCollection(){
mongoTemplate.dropCollection("good_info");
}
/**
* 往集合里插入数据
*/
@Test
void insert(){
User user = new User();
user.setAge(30);
user.setId(200156891);
user.setWorkDay(new Date());
user.setName("栀子花开");
mongoTemplate.insert(user,"good_info");
User user1 = new User();
user1.setAge(30);
user1.setId(200156892);
user1.setWorkDay(new Date());
user1.setName("周杰伦");
mongoTemplate.insert(user1,"good_info");
User user2 = new User();
user2.setAge(40);
user2.setId(200156893);
user2.setWorkDay(new Date());
user2.setName("薛之谦");
mongoTemplate.insert(user2,"good_info");
User user3 = new User();
user3.setAge(40);
user3.setId(200156894);
user3.setWorkDay(new Date());
user3.setName("凤凰传奇");
mongoTemplate.insert(user3,"good_info");
}
/**
* 查询数据
*/
@Test
void queryUserInfo(){
//1.查询所有
System.out.println("------------------------------------------------");
List<User> users = mongoTemplate.findAll(User.class);
users.forEach(System.out::println);
//2.根据 id 查询指定文档
System.out.println("------------------------------------------------");
User byId = mongoTemplate.findById(200156891, User.class);
System.out.println(byId);
//3.根据查询条件进行查询(参数1: 查询条件, 参数2: 返回类型)
System.out.println("------------------------------------------------");
// mongoTemplate.find(new Query(), User.class); //没有查询条件就是查询所有
//a) 等值查询
System.out.println("------------------------------------------------");
List<User> users1 = mongoTemplate.find(Query.query(Criteria.where("name").is("周杰伦")), User.class);
users1.forEach(System.out::println);
//b) > 查询: gt()、>= 查询: gte() 、 < 查询: lt()、<= 查询 lte() 查询
//以 > 为例
System.out.println("------------------------------------------------");
List<User> users2 = mongoTemplate.find(Query.query(Criteria.where("age").gt(30)), User.class);
users2.forEach(System.out::println);
//4.and 查询
System.out.println("------------------------------------------------");
List<User> users3 = mongoTemplate.find(Query.query(Criteria.where("name").is("薛之谦").and("age").is(40)), User.class);
users3.forEach(System.out::println);
//5.or 查询
System.out.println("------------------------------------------------");
Criteria criteria = new Criteria();
criteria.orOperator(
Criteria.where("name").is("周杰伦"),
Criteria.where("name").is("薛之谦")
);
List<User> users4 = mongoTemplate.find(Query.query(criteria), User.class);
users4.forEach(System.out::println);
//6.and 和 or
System.out.println("------------------------------------------------");
Criteria criteria1 = new Criteria();
criteria1.and("age").is(40)
.orOperator(
Criteria.where("name").is("周杰伦"),
Criteria.where("name").is("薛之谦")
);
List<User> users5 = mongoTemplate.find(Query.query(criteria1), User.class);
users5.forEach(System.out::println);
//7.sort
System.out.println("------------------------------------------------");
Query query = new Query();
query.with(Sort.by(Sort.Order.desc("age"))); //desc 降序， asc 升序
mongoTemplate.find(query, User.class);
//8.分页: skip limit
System.out.println("------------------------------------------------");
Query queryPage = new Query();
queryPage.with(Sort.by(Sort.Order.desc("age"))) //desc 降序， asc 升序
.skip(0)
.limit(3);
mongoTemplate.find(queryPage, User.class);
//9.总数
System.out.println("------------------------------------------------");
mongoTemplate.count(new Query(), User.class);
//10.去重 distinct(参数1: 查询条件, 参数2: 去重字段, 参数3: 操作集合, 参数4: 返回类型)
System.out.println("------------------------------------------------");
List<String> name = mongoTemplate.findDistinct(new Query(), "name", User.class, String.class);
//11.json 字符串查询
System.out.println("------------------------------------------------");
Query queryJson = new BasicQuery("{name: '周杰伦', age: '20'}");
List<User> users6 = mongoTemplate.find(queryJson, User.class);
}
/**
* 删除数据
*/
@Test
void deleteUserInfo(){
//1.查询所有
List<User> users = mongoTemplate.findAll(User.class);
users.forEach(System.out::println);
//1.删除所有
// mongoTemplate.remove(new Query(), User.class);
//2.条件删除
mongoTemplate.remove(Query.query(Criteria.where("name").is("栀子花开")), User.class);
System.out.println("====================");
//1.查询所有
List<User> user2 = mongoTemplate.findAll(User.class);
user2.forEach(System.out::println);
}
}