SpringBoot高级篇MongoDB之如何新增文档-白红宇

SpringBoot高级篇MongoDB之如何新增文档

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发布时间：2019-06-23

本文共 6777 字，大约阅读时间需要 22 分钟。

本篇博文为mongodb的curd中一篇，前面介绍简单的查询使用，这一篇重点则放在插入数据;

I. 基本使用

首先是准备好基本环境，可以参考博文

1. 新增一条数据

MongoDB一个基本数据称为document，和mysql不一样，没有强制约束哪些字段，可以随意的插入，下面是一个简单的插入演示

private static final String COLLECTION_NAME = "demo";@Autowiredprivate MongoTemplate mongoTemplate;/** * 新增一条记录 */public void insert() {    JSONObject object = new JSONObject();    object.put("name", "一灰灰blog");    object.put("desc", "欢迎关注一灰灰Blog");    object.put("age", 28);    // 插入一条document    mongoTemplate.insert(object, COLLECTION_NAME);    JSONObject ans = mongoTemplate            .findOne(new Query(Criteria.where("name").is("一灰灰blog").and("age").is(28)), JSONObject.class,                    COLLECTION_NAME);    System.out.println(ans);}

使用的关键地方为一行: mongoTemplate.insert(object, COLLECTION_NAME);

第一个参数为待插入的document

第二个参数为collection name （相当于mysql的table)

执行后输出结果为如下

{"name":"一灰灰blog","_id":{"counter":12472353,"date":1548333180000,"machineIdentifier":14006254,"processIdentifier":17244,"time":1548333180000,"timeSecond":1548333180,"timestamp":1548333180},"age":28,"desc":"欢迎关注一灰灰Blog"}

2. 批量插入

一次插入多条记录，传集合进去即可

/** * 批量插入 */public void insertMany() {    List
     
      > records = new ArrayList<>();    for (int i = 0; i < 3; i++) {        Map
      
        record = new HashMap<>(4);        record.put("wechart", "一灰灰blog");        record.put("blog", Arrays.asList("http://spring.hhui.top", "http://blog.hhui.top"));        record.put("nums", 210);        record.put("t_id", i);        records.add(record);    }    // 批量插入文档    mongoTemplate.insert(records, COLLECTION_NAME);    // 查询插入的内容    List
        result =            mongoTemplate.find(new Query(Criteria.where("wechart").is("一灰灰blog")), Map.class, COLLECTION_NAME);    System.out.println("Query Insert Records: " + result);}

返回结果如下:

Query Insert Records: [{t_id=0, wechart=一灰灰blog, _id=5c49b07cd5b7ee435cbe5022, blog=[http://spring.hhui.top, http://blog.hhui.top], nums=210}, {t_id=1, wechart=一灰灰blog, _id=5c49b07cd5b7ee435cbe5023, blog=[http://spring.hhui.top, http://blog.hhui.top], nums=210}, {t_id=2, wechart=一灰灰blog, _id=5c49b07cd5b7ee435cbe5024, blog=[http://spring.hhui.top, http://blog.hhui.top], nums=210}]

3. upsert，不存在才插入

我们希望在插入之前，判断数据是否存在，如果不存在则插入；如果存在则更新；此时就可以采用upsert来使用，一般三个参数

mongoTemplate.upsert(Query query, Update update, String collectionName)

第一个为查询条件，第二个为需要更新的字段，最后一个指定对应的collection，一个简单的实例如下

/** * 数据不存在，通过 upsert 新插入一条数据 * * set 表示修改key对应的value * addToSet 表示在数组中新增一条 */public void upsertNoMatch() {    // addToSet 表示将数据塞入document的一个数组成员中    UpdateResult upResult = mongoTemplate.upsert(new Query(Criteria.where("name").is("一灰灰blog").and("age").is(100)),            new Update().set("age", 120).addToSet("add", "额外增加"), COLLECTION_NAME);    System.out.println("nomatch upsert return: " + upResult);    List
    
      re = mongoTemplate            .find(new Query(Criteria.where("name").is("一灰灰blog").and("age").is(120)), JSONObject.class,                    COLLECTION_NAME);    System.out.println("after upsert return should not be null: " + re);    System.out.println("------------------------------------------");}

输出结果如下:

nomatch upsert return: AcknowledgedUpdateResult{matchedCount=0, modifiedCount=0, upsertedId=BsonObjectId{value=5c49b07ce6652f7e1add1ea2}}after upsert return should not be null: [{"add":["额外增加"],"name":"一灰灰blog","_id":{"counter":14491298,"date":1548333180000,"machineIdentifier":15099183,"processIdentifier":32282,"time":1548333180000,"timeSecond":1548333180,"timestamp":1548333180},"age":120}]------------------------------------------

4. upsert，存在则更新

前面的demo是演示不存在，那么存在数据呢?

/** * 只有一条数据匹配，upsert 即表示更新 */public void upsertOneMatch() {    // 数据存在，使用更新    UpdateResult result = mongoTemplate.upsert(new Query(Criteria.where("name").is("一灰灰blog").and("age").is(120)),            new Update().set("age", 100), COLLECTION_NAME);    System.out.println("one match upsert return: " + result);    List
    
      ans = mongoTemplate            .find(new Query(Criteria.where("name").is("一灰灰blog").and("age").is(100)), JSONObject.class,                    COLLECTION_NAME);    System.out.println("after update return should be one: " + ans);    System.out.println("------------------------------------------");}

输出结果如下，注意下面的输出数据的 _id，正视前面插入的那条数据，两个数据唯一的不同，就是age被修改了

one match upsert return: AcknowledgedUpdateResult{matchedCount=1, modifiedCount=1, upsertedId=null}after update return should be null: [{"add":["额外增加"],"name":"一灰灰blog","_id":{"counter":14491298,"date":1548333180000,"machineIdentifier":15099183,"processIdentifier":32282,"time":1548333180000,"timeSecond":1548333180,"timestamp":1548333180},"age":100}]

5. upsert，多条满足时

如果query条件命中多条数据，怎么办？会修改几条数据呢？

/** * 两条数据匹配时，upsert 将只会更新一条数据 */public void upsertTwoMatch() {    // 多条数据满足条件时，只会修改一条数据    System.out.println("------------------------------------------");    List
    
      re = mongoTemplate            .find(new Query(Criteria.where("name").is("一灰灰blog").and("age").in(Arrays.asList(28, 100))),                    JSONObject.class, COLLECTION_NAME);    System.out.println("original record: " + re);    UpdateResult result = mongoTemplate            .upsert(new Query(Criteria.where("name").is("一灰灰blog").and("age").in(Arrays.asList(28, 100))),                    new Update().set("age", 120), COLLECTION_NAME);    System.out.println("two match upsert return: " + result);    re = mongoTemplate.find(new Query(Criteria.where("name").is("一灰灰blog").and("age").is(120)), JSONObject.class,            COLLECTION_NAME);    System.out.println("after upsert return size should be 1: " + re);    System.out.println("------------------------------------------");}

根据实际输出进行查看，发现只有一条数据被修改；另外一条保持不变，结果如下

------------------------------------------original record: [{"name":"一灰灰blog","_id":{"counter":12472353,"date":1548333180000,"machineIdentifier":14006254,"processIdentifier":17244,"time":1548333180000,"timeSecond":1548333180,"timestamp":1548333180},"age":28,"desc":"欢迎关注一灰灰Blog"}, {"add":["额外增加"],"name":"一灰灰blog","_id":{"counter":14491298,"date":1548333180000,"machineIdentifier":15099183,"processIdentifier":32282,"time":1548333180000,"timeSecond":1548333180,"timestamp":1548333180},"age":100}]two match upsert return: AcknowledgedUpdateResult{matchedCount=1, modifiedCount=1, upsertedId=null}after upsert return size should be 1: [{"name":"一灰灰blog","_id":{"counter":12472353,"date":1548333180000,"machineIdentifier":14006254,"processIdentifier":17244,"time":1548333180000,"timeSecond":1548333180,"timestamp":1548333180},"age":120,"desc":"欢迎关注一灰灰Blog"}]------------------------------------------