[英]Spring Boot Data and MongoDB - Filter Subdocument Array Query
我試圖使用Spring來查詢Mongo存儲庫並過濾數組子文檔。 我已經引用了如何使用mongodb過濾子文檔中的數組 ,但是想知道是否有更合適的或java結構化的方法來使用Spring。
我目前正在使用速記存儲庫接口表示法,但我正在使用未過濾的數組返回完整的文檔。
PersonRepository.java
@Repository
public interface PersonRepository extends MongoRepository <Person, String> {
List<Person> findByAddressZipCode(@Param("zip") int zip);
}
Person.java
@Document
public class Person {
@Id
private String id;
private String firstName;
private String lastName;
private List<Address> address;
}
Address.java
public class Address {
private int zip;
}
樣本輸入
{
"firstName":"George",
"lastName":"Washington",
"address":[{
"zip":"12345"
},{
"zip":"98765"
},{
"zip":"12345"
}]
}
預期產出
{
"firstName":"George",
"lastName":"Washington",
"address":[{
"zip":"12345"
},{
"zip":"12345"
}]
}
實際產出
{
"firstName":"George",
"lastName":"Washington",
"address":[{
"zip":"12345"
},{
"zip":"98765"
},{
"zip":"12345"
}]
}
那么,在Spring Data中,這種查詢並不trivial
。
壞消息:
Spring Data Repository沒有MongoDB Aggregation
解決方案。 所以,你不能在MongoRepository中實現任何方法,比如aggregateBy...
好消息:
Spring Data提供了MongoTemplate
類,允許您執行復雜查詢,就像在標准MongoDB shell中一樣。
因此,由於您只想exclude
與某些條件不匹配的子文檔,我們需要定義聚合pipelines
。
我假設:
zip codes are Numeric (In your example is string)
And, to exclude subdocument, we filter by `zip`
There is no any other filter
MongoDB聚合將是:
db.person.aggregate([
{$unwind: "$address"},
{$match: {"address.zip": 12345}},
{$group: { _id: { "firstName":"$firstName", "lastName":"$lastName", _id:"$_id" }, address: { $push: "$address" } } },
{$project: {_id:0, "firstName":"$_id.firstName", "lastName":"$_id.lastName", "address": "$address"}}
])
如果所有過濾器都成功,我們得到:
[
{
"address" : [
{
"zip" : 12345
},
{
"zip" : 12345
}
],
"firstName" : "George",
"lastName" : "Washington"
}
]
首先,找到你需要添加的mongo-config.xml
:
<!-- Define the mongoDbFactory with your database Name --> <mongo:db-factory uri="mongodb://user:pass@localhost:27017/db"/> <!-- Define the MongoTemplate --> <bean id="mongoTemplate" class="org.springframework.data.mongodb.core.MongoTemplate"> <constructor-arg name="mongoDbFactory" ref="mongoDbFactory" /> </bean>
MongoTemplate
是Spring的MongoDB支持的中心類,提供與數據庫交互的功能集。 模板...
提供域對象和MongoDB文檔之間的映射。 更多信息
其次,在@Service
類中,添加以下代碼以加載到@PostConstruct
@Autowired private MongoOperations mongoOperations; ... public List<Person> findByAddressZipCode(int zip) { List<AggregationOperation> list = new ArrayList<AggregationOperation>(); list.add(Aggregation.unwind("address")); list.add(Aggregation.match(Criteria.where("address.zip").is(zip))); list.add(Aggregation.group("firstName", "lastName").push("address").as("address")); list.add(Aggregation.project("firstName", "lastName", "address")); TypedAggregation<Person> agg = Aggregation.newAggregation(Person.class, list); return mongoOperations.aggregate(agg, Person.class, Person.class).getMappedResults(); }
注意: Person
和Address
都應該有默認的空構造函數!
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