我在mongo中存储了一个如下所示的对象(这是我在查看文档时在RoboMongo中的显示方式:]
{
"_id": ObjectId("5e579c8674f69d1c1451f3ae"),
...
"timestamp": NumberLong(1582800002779),
...
"_class": "regular"
}
我存储的对象是这样定义的:
public class MyObjectModel {
@Id
@Field(value = ID_FIELD_NAME)
private String id;
@Field(value = TIMESTAMP_FIELD_NAME)
private Long timestamp;
...
}
我的意图是获取时间范围内的对象列表。这就是我用spring数据mongo db创建查询的方式:
public List<Criteria> generateAllCriteria() {
List<Criteria> criteriaList = new ArrayList<>();
Optional.ofNullable(searchCriteria.getFromTimestamp()).map(ts -> criteriaList.add(generateFromTimestampCriteria(ts)));
Optional.ofNullable(searchCriteria.getToTimestamp()).map(ts -> criteriaList.add(generateToTimestampCriteria(ts)));
return criteriaList;
}
private Criteria generateFromTimestampCriteria(Long fromTimestamp) {
Criteria critFromTimestamp = Criteria.where(TIMESTAMP_FIELD_NAME).gte(fromTimestamp);
log.debug("From Timestamp criteria {}", critFromTimestamp.getCriteriaObject().toJson());
return critFromTimestamp;
}
private Criteria generateToTimestampCriteria(Long toTimestamp) {
Criteria critToTimestamp = Criteria.where(TIMESTAMP_FIELD_NAME).lt(toTimestamp);
log.debug("To Timestamp criteria {}", critToTimestamp.getCriteriaObject().toJson());
return critToTimestamp;
}
...
List<Criteria> criteriaList = generateAllCriteria();
Criteria finalCriteria = new Criteria();
finalCriteria = finalCriteria.andOperator(criteriaList.toArray(new Criteria[criteriaList.size()]));
log.debug("Final criteria {}", finalCriteria);
Query query = new Query();
query.addCriteria(finalCriteria);
List<MyObjectModel> myObjects = mongoTemplate.find(query, MyObjectModel.class);
当我显示查询时,它们是以下内容:
From Timestamp criteria { "timestamp" : { "$gte" : { "$numberLong" : "1582714365857" } } }
To Timestamp criteria { "timestamp" : { "$lt" : { "$numberLong" : "1582887165858" } } }
最终的查询条件似乎是这样:
o.s.data.mongodb.core.MongoTemplate - find using query: { "$and" : [{ "timestamp" : { "$gte" : { "$numberLong" : "1582714365857" } } }, { "timestamp" : { "$lt" : { "$numberLong" : "1582887165858" } } }] } fields: Document{{}} for class: class mypackage.model.MyObjectModel in collection: myObjectModel
乍看之下似乎还可以,但是当我手动对Mongo运行它时,它不会返回任何记录,我认为这是不正确的。这正是我在Mongo上运行的内容:
db.getCollection('my-collection').find({ "$and" : [{ "timestamp" : { "$gte" : { "$numberLong" : "1582707873806" } } }, { "timestamp" : { "$lt" : { "$numberLong" : "1582887165858" } } }] })
并且它显然不返回任何记录。但是,当我修改查询并摆脱$ numberLong:
db.getCollection('my-collection').find({ "$and" : [{ "timestamp" : { "$gte" : 1582707873806 } }, { "timestamp" : { "$lt" : 1582887165858 } }] })
它像一种魅力。
有人可以启发我并解释我做错了什么吗?应该如何以正确的方式完成?如何使spring数据mongo创建适当的查询?
不用说,字符串和整数工作正常。仅约LONG s。
提前感谢您的帮助。
据我了解:
并且假设您的模型是:
public class Regular {
@Id
private String id;
@Field
private Long timestamp;
}
然后可能的解决方案(恕我直言,简短得多)是:
// exists(true) is a "hack" to return the elements in case both from/to are null
public List<Regular> find(Long from, Long to) {
var criteria = where("timestamp").exists(true);
if(from != null) {
criteria.gte(from);
}
if(to != null) {
criteria.lte(to);
}
return mongoTemplate.find(Query.query(criteria), Regular.class);
}
PS。我已经用Spring Boot 2.2.4和Mongo 3.6检查了它。
PS2。仍然可以通过额外的if条件处理from / to均为null的情况,然后删除exists(true)。