Spring Data MongoDB删除

在Spring Data MongoDB中，可以使用remove()和findAndRemove()删除文档。

• 1. remove() - 删除一个或多个文档。
• 1. findAndRemove() - 删除单个文档，并返回删除的文档。

常见错误：
不要使用findAndRemove()执行批量删除，因为只有符合条件的第一个文档被删除了。

1. 删除文档实例

import java.util.ArrayList;import java.util.List;import org.springframework.context.ApplicationContext;import org.springframework.context.annotation.AnnotationConfigApplicationContext;import org.springframework.data.mongodb.core.MongoOperations;import org.springframework.data.mongodb.core.query.Criteria;import org.springframework.data.mongodb.core.query.Query;import com.mkyong.config.SpringMongoConfig;import com.mkyong.model.User;/** * Delete example * * @author mkyong * */public class DeleteApp {    public static void main(String[] args) {        ApplicationContext ctx =                      new AnnotationConfigApplicationContext(SpringMongoConfig.class);        MongoOperations mongoOperation =                      (MongoOperations) ctx.getBean("mongoTemplate");        // insert 6 users for testing        List<User> users = new ArrayList<User>();        User user1 = new User("1001", "ant", 10);        User user2 = new User("1002", "bird", 20);        User user3 = new User("1003", "cat", 30);        User user4 = new User("1004", "dog", 40);        User user5 = new User("1005", "elephant", 50);        User user6 = new User("1006", "frog", 60);        users.add(user1);        users.add(user2);        users.add(user3);        users.add(user4);        users.add(user5);        users.add(user6);        mongoOperation.insert(users, User.class);        Query query1 = new Query();        query1.addCriteria(Criteria.where("name").exists(true)            .orOperator(                           Criteria.where("name").is("frog"),                           Criteria.where("name").is("dog")                        ));        mongoOperation.remove(query1, User.class);        Query query2 = new Query();        query2.addCriteria(Criteria.where("name").is("bird"));        User userTest2 = mongoOperation.findOne(query2, User.class);        mongoOperation.remove(userTest2);        // The first document that matches the query is returned and also        // removed from the collection in the database.        Query query3 = new Query();        query3.addCriteria(Criteria.where("name").is("ant"));        User userTest3 = mongoOperation.findAndRemove(query3, User.class);        System.out.println("Deleted document : " + userTest3);        // either cat or elephant is deleted only,                // common mistake, don't use for batch delete.        /*          Query query4 = new Query();                  query4.addCriteria(Criteria.where("name") .exists(true)               .orOperator(                             Criteria.where("name").is("cat"),                     Criteria.where("name").is("elephant")                        )                  );          mongoOperation.findAndRemove(query4, User.class);          System.out.println("Deleted document : " + userTest4);         */        System.out.println("\nAll users : ");        List<User> allUsers = mongoOperation.findAll(User.class);        for (User user : allUsers) {            System.out.println(user);        }        mongoOperation.dropCollection(User.class);    }}

输出：

Deleted document : User [id=5162e0153004c3cb0a907370, ic=1001, name=ant, age=10]All users :User [id=5162e0153004c3cb0a907372, ic=1003, name=cat, age=30]User [id=5162e0153004c3cb0a907374, ic=1005, name=elephant, age=50]