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;java
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首先是准备好基本环境,能够参考博文git
MongoDB一个基本数据称为document,和mysql不同,没有强制约束哪些字段,能够随意的插入,下面是一个简单的插入演示github
private static final String COLLECTION_NAME = "demo"; @Autowired private 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);
spring
执行后输出结果为以下sql
{"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"}
一次插入多条记录,传集合进去便可mongodb
/** * 批量插入 */ public void insertMany() { List<Map<String, Object>> records = new ArrayList<>(); for (int i = 0; i < 3; i++) { Map<String, Object> 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<Map> result = mongoTemplate.find(new Query(Criteria.where("wechart").is("一灰灰blog")), Map.class, COLLECTION_NAME); System.out.println("Query Insert Records: " + result); }
返回结果以下:数组
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}]
咱们但愿在插入以前,判断数据是否存在,若是不存在则插入;若是存在则更新;此时就能够采用upsert来使用,通常三个参数spring-boot
mongoTemplate.upsert(Query query, Update update, String collectionName)
第一个为查询条件,第二个为须要更新的字段,最后一个指定对应的collection,一个简单的实例以下学习
/** * 数据不存在,经过 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", "额外增长"), COLLECTION_NAME); System.out.println("nomatch upsert return: " + upResult); List<JSONObject> 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("------------------------------------------"); }
输出结果以下:
nomatch upsert return: AcknowledgedUpdateResult{matchedCount=0, modifiedCount=0, upsertedId=BsonObjectId{value=5c49b07ce6652f7e1add1ea2}} after upsert return should not be null: [{"add":["额外增长"],"name":"一灰灰blog","_id":{"counter":14491298,"date":1548333180000,"machineIdentifier":15099183,"processIdentifier":32282,"time":1548333180000,"timeSecond":1548333180,"timestamp":1548333180},"age":120}] ------------------------------------------
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<JSONObject> 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("------------------------------------------"); }
输出结果以下,注意下面的输出数据的 _id
,正视前面插入的那条数据,两个数据惟一的不一样,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":["额外增长"],"name":"一灰灰blog","_id":{"counter":14491298,"date":1548333180000,"machineIdentifier":15099183,"processIdentifier":32282,"time":1548333180000,"timeSecond":1548333180,"timestamp":1548333180},"age":100}]
若是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() { // 多条数据知足条件时,只会修改一条数据 System.out.println("------------------------------------------"); List<JSONObject> 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;另一条保持不变,结果以下
------------------------------------------ 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":["额外增长"],"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"}] ------------------------------------------
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