Hibernate many-to-many 매핑과 질의

Question

HQL을 사용하는 데 어려움을 겪고 있습니다. 나는 한 테이블에 여러 경쟁자가있는 어플리케이션을 가지고 있습니다. 그렇다면 나는 경쟁자와 경쟁하는 경쟁을합니다. 각 경쟁에는 경쟁자가 여럿있을 수 있습니다. 각 경쟁자는 여러 경기에 참가할 수 있습니다. (사실, 나는 "라운드 로빈"경쟁을 설정하고 있으므로 모든 경쟁자는 다른 경쟁자와 경쟁 할 수 있도록 많은 경쟁자가 될 것입니다.)

직접 조인 테이블을 만드는 대신, Hibernate의 XML을 사용하여 join 테이블을 생성한다. 궁극적으로, 나는 다음과 같은 HQL 쿼리 같은 것을 쓸 수 있어야한다고 생각 : 실제로 더 큰 쿼리의 일부

select count(*) from Competition c where c.competitor.id = :competitorId 

간단한 쿼리. 내 의도는 주어진 경쟁자가 참가하는 대회 수를 세는 것입니다. 내가 만나는 문제는 다음과 같은 오류입니다.

org.hibernate.QueryException: could not resolve property: competitor of: com.sodapopsoftware.imagewar.model.db.Competition [ select count(*) from com.sodapopsoftware.imagewar.model.db.Competition c where c.competitor.id = :competitorId ] 

다음은 경쟁자 및 경쟁자를위한 나의 매핑입니다.

경쟁

<?xml version="1.0"?> 
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> 
<hibernate-mapping> 
<class name="com.sodapopsoftware.imagewar.model.db.Competition" table="competition"> 

    <meta attribute="use-in-tostring">true</meta> 
    <meta attribute="extra-import">java.util.Set</meta> 
    <meta attribute="extra-import">java.util.TreeSet</meta> 

    <id name="competitionId" column="competition_id" type="int"> 
     <meta attribute="scope-set">protected</meta> 
     <meta attribute="field-description">Primary Key</meta> 
     <meta attribute="use-in-equals">true</meta> 
     <generator class="native" /> 
    </id> 
    <many-to-one name="league" column="league_id" unique="false" not-null="true" 
     class="com.sodapopsoftware.imagewar.model.db.League" 
    /> 
    <property name="dateAdded" column="date_added" type="date" not-null="true"> 
     <meta attribute="field-description">When the league was created</meta> 
    </property> 
    <set name="competitors" table="competition_competitors" sort="com.sodapopsoftware.imagewar.model.util.CompetitorIdComparator"> 
     <meta attribute="property-type"><![CDATA[Set<Competitor>]]></meta> 
     <meta attribute="default-value"><![CDATA[new TreeSet<Competitor>()]]></meta> 
     <key column="competition_id"/> 
     <many-to-many column="competitor_id" 
      unique="false" 
      class="com.sodapopsoftware.imagewar.model.db.Competitor"/> 
    </set> 
</class> 
</hibernate-mapping> 

경쟁자 쿼리가 참조 구문 (ManyToOne)하지만 하나/다 대다 명시 적 필요를 사용

<?xml version="1.0"?> 
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> 
<hibernate-mapping> 
<class name="com.sodapopsoftware.imagewar.model.db.Competitor" table="competitor"> 

    <meta attribute="use-in-tostring">true</meta> 
    <meta attribute="extra-import">java.lang.Comparable</meta> 
    <meta attribute="implements">Comparable<![CDATA[<]]> Competitor <![CDATA[>]]></meta> 
    <meta attribute="class-code"> private static final long serialVersionUID = 1L;</meta> 
    <meta attribute="class-code"> 
public int compareTo(Competitor that) { 
    if (that != null) { 
     return this.getCompetitorId() - that.getCompetitorId(); 
    } 
    return 1; 
} 
    </meta> 
    <id name="competitorId" column="competitor_id" type="int"> 
     <meta attribute="scope-set">protected</meta> 
     <meta attribute="use-in-equals">true</meta> 
     <generator class="native" /> 
    </id> 
    <many-to-one name="league" column="league_id" unique="false" not-null="true" 
     class="com.sodapopsoftware.imagewar.model.db.League" 
    /> 
    <property name="name" column="name" type="string" not-null="true"> 
     <meta attribute="field-description">Gives this competitor a name</meta> 
    </property> 
    <property name="nameNormalized" column="name_normalized" unique="true" type="string" not-null="true"> 
     <meta attribute="field-description">Same as name, but lower case for searching</meta> 
    </property> 
    <property name="description" column="description" type="string"> 
     <meta attribute="field-description">Describes this competitor</meta> 
    </property> 
    <property name="linkImageThumbnail" column="link_image_thumbnail" type="string" not-null="true"> 
     <meta attribute="field-description">Link to the thumbnail image for this competitor</meta> 
    </property> 
    <property name="linkImageFullSized" column="link_image_full_sized" type="string" not-null="true"> 
     <meta attribute="field-description">Link to the full-sized image for this competitor</meta> 
    </property> 
    <property name="dateAdded" column="date_added" type="date" not-null="true"> 
     <meta attribute="field-description">When the competitor was created</meta> 
    </property> 
</class> 
</hibernate-mapping> 

Answer 1

는 별명을 가지고 가입 요소들

select count(*) from Competition c join c.competitors co where co.id = :competitorId