Spring Boot MongoDB 查詢操作 (BasicQuery ,BSON)

zhaozhangxiao 發表於 2021-09-23
MongoDB Spring

參考:www.cnblogs.com/bookc/p/9887922.ht...
MongoDB 查詢有四種方式:Query,TextQuery,BasicQuery 和 Bson ,網上太多關於 Query 的查詢方式,本文只記錄 BasicQuery和Bson 的方式,BasicQuery 相對於 Query 更加的靈活,BasicQuery 就是 Query 的擴充套件,BasicQuery 可以返回指定列資料。最靈活的是Bson方式。

大寫的採坑經驗

1.MongoDB 雖然儲存很靈活,但是,不要儲存Map型別的,不要儲存Map型別的,不要儲存Map型別的。儘量儲存強型別的,儘量儲存強型別的,儘量儲存強型別的。如果有Map型別的,對於查詢指定列的,只能用Bson ,如果是強型別的,就可以直接用Query,TextQuery。

2.複雜型別查詢 可以考慮 Bson 方式,Bson 請參考文章最後。

安裝Maven包

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-mongodb</artifactId>
</dependency>

測試資料程式碼

 for (Long i = 0L; i < 10L; i++) {
     MongoDBTestVo vo=new MongoDBTestVo();
     vo.setUserId(i);
     vo.setEmail("[email protected]");
     vo.setName("test"+i.toString());
     vo.setPhone(i.toString());
     vo.setCreateDate(new Date());
     mongoTemplate.insert(vo,"mongodbtest");
}

Spring Boot MongoDB 查詢操作 (BasicQuery ,BSON) MongoDBTestVo Code

單條件查詢

DBObject obj = new BasicDBObject();
obj.put("userId", new BasicDBObject("$gte", 2)); // userId>=2的條件
//obj.put("userId", 2); userId=2 的條件

Query query = new BasicQuery(obj.toString()); 
List<MongoDBTestVo> result = mongoTemplate.find(query, MongoDBTestVo.class, "mongodbtest");

多條件查詢

BasicDBList basicDBList = new BasicDBList();
basicDBList.add(new BasicDBObject("userId", 2L));
basicDBList.add(new BasicDBObject("name","test2"));

DBObject obj = new BasicDBObject();
obj.put("$and", basicDBList);

Query query = new BasicQuery(obj.toString());

List<MongoDBTestVo> result = mongoTemplate.find(query, MongoDBTestVo.class, "mongodbtest");

檢視指定列的資料

DBObject obj = new BasicDBObject();
obj.put("userId", new BasicDBObject("$gte", 2));

BasicDBObject fieldsObject = new BasicDBObject();
fieldsObject.put("userId", 1);
fieldsObject.put("name", 1);

Query query = new BasicQuery(obj.toString(), fieldsObject.toString());

List<Map> result = mongoTemplate.find(query, Map.class, "mongodbtest");

BasicQuery查詢語句可以指定返回欄位,建構函式BasicQuery(DBObject queryObject, DBObject fieldsObject),fieldsObject 這個欄位可以指定返回欄位

fieldsObject.put(key,value)

        key:欄位

       value:

         說明:

              1或者true表示返回欄位

             0或者false表示不返回該欄位

           _id:預設就是1,沒指定返回該欄位時,預設會返回,除非設定為0是,就不會返回該欄位。

指定返回欄位,有時文件欄位多並資料大時,我們指定返回我們需要的欄位,這樣既節省傳輸資料量,減少了記憶體消耗,提高了效能,在資料大時,效能很明顯的。

Bson查詢方式

Bson bson = Filters.and(Arrays.asList(
                    Filters.gte("createdTime", Calendar.getInstance().getTime()),
                    Filters.gte("apis.count", 1)));
MongoCursor<Document> cursor = null; try {
    FindIterable<Document> findIterable = mongoTemplate.getCollection("mongodbtest").find(bson);
    cursor = findIterable.iterator();
    List<MongoDBTestVo> list = new ArrayList<>(); while (cursor.hasNext()) {
          Document object = cursor.next();
          MongoDBTestVo entity = JSON.parseObject(object.toJson(), MongoDBTestVo.class);
          list.add(entity);
     } return list;
} finally { if (cursor != null) {
       cursor.close();
   }
}

Bson返回指定列

Bson bson = Filters.and(Arrays.asList(
                    Filters.gte("createdTime", Calendar.getInstance().getTime()),
                    Filters.gte("apis.count", 1)));

BasicDBObject fieldsObject = new BasicDBObject();
fieldsObject.put("apis.count", 1);
fieldsObject.put("_id", 0);

MongoCursor<Document> cursor = null; try {
    FindIterable<Document> findIterable = mongoTemplate.getCollection("mongodbtest").find(bson).projection(Document.parse(fieldsObject.toString()));
    cursor = findIterable.iterator();
    List<MongoDBTestVo> list = new ArrayList<>(); while (cursor.hasNext()) {
          Document object = cursor.next();
          MongoDBTestVo entity = JSON.parseObject(object.toJson(), MongoDBTestVo.class);
          list.add(entity);
     } return list;
} finally { if (cursor != null) {
       cursor.close();
   }
}

Bson 排序

Bson bson = Filters.and(Arrays.asList(

Filters.gte("createdTime", Calendar.getInstance().getTime()),
Filters.gte("apis.count", 1)));

BasicDBObject fieldsObject = new BasicDBObject();
fieldsObject.put("apis.count", 1);
fieldsObject.put("_id", 0);

BasicDBObject sort = new BasicDBObject();
sort.put("createdTime", 1);

MongoCursor<Document> cursor = null;
try {
    FindIterable<Document> findIterable = mongoTemplate.getCollection("mongodbtest").find(bson).projection(Document.parse(fieldsObject.toString())).sort(sort);
    cursor = findIterable.iterator();
    List<MongoDBTestVo> list = new ArrayList<>();
    while (cursor.hasNext()) {
          Document object = cursor.next();
          MongoDBTestVo entity = JSON.parseObject(object.toJson(), MongoDBTestVo.class);
          list.add(entity);
     }
     return list;
} finally {
   if (cursor != null) {
       cursor.close();
   }
}
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