Spring Data MongoDB的核心用法 附示例代码

User user = new User("张三", 25);
User saved = mongoTemplate.insert(user); // 返回带主键的对象

User user = new User("张三", 25);
User saved = mongoTemplate.insert(user); // 返回带主键的对象

mongoTemplate.save(user); 

Query query = Query.query(Criteria.where("id").is(userId));
Update update = new Update().set("name", "李四");
// 更新第一个匹配项
mongoTemplate.updateFirst(query, update, "userDao");
// 更新所有匹配项
mongoTemplate.updateMulti(query, update, "userDao");

// 1. 根据主键删除（只需设置 id 字段）
User user = new User();
user.setId("60d..."); 
mongoTemplate.remove(user);
// 2. 根据条件删除
Query query = Query.query(Criteria.where("age").lt(18));
mongoTemplate.remove(query, "userDao");

// 查询全部
List<User> all = mongoTemplate.findAll(User.class);
// 根据 ID 查询
User user = mongoTemplate.findById("60d...", User.class);
// 查询第一条匹配结果
User first = mongoTemplate.findOne(query, User.class);
// 查询所有匹配结果
List<User> list = mongoTemplate.find(query, User.class);

// 等价于 db.user.find({name: {$exists: false}})
Query query = Query.query(Criteria.where("name").exists(false));

Query query = new Query(Criteria.where("age").gt(20).lt(30));
List<User> users = mongoTemplate.find(query, User.class);

// 包含匹配（任意位置）→ SQL: LIKE '%name%'
Query query = Query.query(Criteria.where("name").regex(Pattern.quote(name), "i"));
// 前缀匹配 → SQL: LIKE 'name%'
Query query = Query.query(Criteria.where("name").regex("^" + Pattern.quote(name), "i"));
// 后缀匹配 → SQL: LIKE '%name'
Query query = Query.query(Criteria.where("name").regex(Pattern.quote(name) + "$", "i"));

Query query = Query.query(Criteria.where("name").regex("张"));
List<String> distinctNames = mongoTemplate.findDistinct(query, "name", User.class, String.class);

Criteria criteria = Criteria.where("name").is("张三").and("age").gt(20);
Query query = Query.query(criteria);

Criteria criteria = new Criteria().orOperator(
    Criteria.where("name").is("张三"),
    Criteria.where("age").gt(20)
);
Query query = Query.query(criteria);

Criteria and1 = Criteria.where("name").is("张三").and("age").is(18);
Criteria and2 = Criteria.where("name").is("李四").and("age").is(20);
Criteria or = new Criteria().orOperator(and1, and2);
List<User> result = mongoTemplate.find(Query.query(or), User.class);

Query query = new Query(Criteria.where("age").gte(2));
query.with(Sort.by(Sort.Direction.DESC, "age")); // 按 age 降序
List<User> list = mongoTemplate.find(query, User.class);

// 第0页（第一页），每页2条
Pageable pageable = PageRequest.of(0, 2);
Query query = new Query().with(pageable);
List<User> pageData = mongoTemplate.find(query, User.class);
// 分页 + 排序
Pageable pageable = PageRequest.of(0, 2, Sort.by(Sort.Direction.ASC, "name"));

TypedAggregation<User> agg = Aggregation.newAggregation(
    User.class,
    Aggregation.group().count().as("count")
);
AggregationResults<Map> result = mongoTemplate.aggregate(agg, Map.class);
Long total = (Long) result.getUniqueMappedResult().get("count");

TypedAggregation<User> agg = Aggregation.newAggregation(
    User.class,
    Aggregation.match(Criteria.where("name").is("张三")), // 先过滤
    Aggregation.group("name").count().as("count")        // 再分组
);
List<Map> results = mongoTemplate.aggregate(agg, Map.class).getMappedResults();
for (Map map : results) {
    System.out.println("姓名: " + map.get("_id") + ", 数量: " + map.get("count"));
}

@Document(collection = "users")
@TypeAlias("user") // 可选：用简短别名替代全类名
public class User { ... }

@Configuration
public class MongoConfig {
    @Bean
    public MongoCustomConversions mongoCustomConversions() {
        return new MongoCustomConversions(Collections.emptyList());
    }
}

Query query = Query.query(Criteria.where("_id").is(userId));
Update update = new Update().set("name", "新名字").set("age", 30);
mongoTemplate.updateFirst(query, update, "users");

String keyword = "张*三";
String escapedKeyword = Pattern.quote(keyword); // 转义为字面量
Query query = Query.query(Criteria.where("name").regex(escapedKeyword, "i"));

Query query = new Query(
    Criteria.where("_id").gt(lastId)
).limit(20).with(Sort.by(Sort.Direction.ASC, "_id"));

public class User {
    @Field("user_name")
    private String userName;
    @Field("created_at")
    private Date createdAt;
}

import org.bson.types.ObjectId;
@Id
private ObjectId id;

AggregationResults<Document> raw = mongoTemplate.aggregate(agg, Document.class);
System.out.println(raw.getRawResults());