Get your ideas to market faster with a flexible, AI-ready database. MongoDB makes working with data easy.
这是MongoDB官方文档。了解如何在灵活的文档中存储数据、创建MongoDB Atlas部署以及使用工具和集成的生态系统。
public MongoDbV2Source() Creates an instance of MongoDbV2Source class.Method Details additionalColumns public Object additionalColumns() Get the additionalColumns property: Specifies the additional columns to be added to source data. Type: array of objects(AdditionalColumns) (or Expression with resultTy...
class: "$class" }, averageScore: { $avg: "$score" } } } ]) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 在上面的代码中,我们使用了$group操作符将文档按照学科和班级分组,并使用$avg操作符计算每个班级在每个学科的平均成绩。这个聚合操作将返回一个文档数组,每个文档包含学科、班级和该班级在...
public MongoDbSource() Creates an instance of MongoDbSource class.Method Details additionalColumns public Object additionalColumns() Get the additionalColumns property: Specifies the additional columns to be added to source data. Type: array of objects(AdditionalColumns) (or Expression with resultType ...
如果索引字段包含数组值,MongoDB会为数组的每个元素创建单独的索引条目。这些多键索引允许查询通过匹配数组中的元素来获取包含数组的文档。 代码语言:javascript 代码运行次数:0 运行 AI代码解释 db.classes.insertMany([{"classname":"class1","students":[{name:'jack',age:20},{name:'tom',age:22},{name:...
@SpringBootTest public class MongoTemplateTest { @Autowired private MongoTemplate mongoTemplate; } 然后,实现了UserEntity对象的增、删、改、查功能。 代码语言:javascript 代码运行次数:0 运行 AI代码解释 @Test public void testSaveUser() { UserEntity user=new UserEntity(); user.setId(1L); user.set...
"DBInstanceClass": "dds.mongo.mid", "Engine": "MongoDB", "ReadonlyReplicas": 1, "ReplicationFactor": 3, "KindCode": 18, "CapacityUnit": 100, "ChargeType": "PostPaid", "StorageType": "cloud_essd1", "SecondaryZoneId": "cn-hangzhou-i", "HiddenZoneId": "cn-hangzhou-h", "Destr...
db.table7.insertMany([ { "_id" : 1, "char" : "Brisbane", "class" : "monk", "lvl" : 4 }, { "_id" : 2, "char" : "Eldon", "class" : "alchemist", "lvl" : 3 }, { "_id" : 3, "char" : "Meldane", "class" : "ranger", "lvl" : 3 } ]); ...
示例2:把count大于20的class name修改为c4,设置multi为true > db.classes.update({"count":{$gt:20}},{$set:{"name":"c4"}},false,true)> db.classes.find() {"_id": ObjectId("5030f3a3721e16c4ab180cd9"),"name":"c4","count":30} ...