Java/JPA with Error
[해결 방법] org.hibernate.QueryException
HJ0216
2023. 9. 26. 17:34
👉 기본 환경
- Language: Java
- DB: H2 Database
- IDE: IntelliJ
⌨️ 코드
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public class Main {
public static void main(String[] args) {
// 생략
try {
Team team = new Team();
team.setName("Team");
em.persist(team);
Member member = new Member();
member.setName("Member");
member.setAge(10);
member.setTeam(team);
member.setType(MemberType.ADMIN);
em.persist(member);
em.flush();
em.clear();
String query = "select t.members.name from Team t";
List<String> members = em.createQuery(query, String.class)
.getResultList();
tx.commit(); // transaction 종료 후 commit
} catch (Exception e) {
tx.rollback(); // 문제가 생길 경우, rollback 진행
e.printStackTrace();
} finally {
em.close(); // tx에 문제가 생기더라도 em 반드시 종료
}
emf.close();
// 트랜잭션 단위로 관리되는 Entity Manager는 Tx가 종료되면 close가 되어야하지만, emf는 Application 종료 시, close되어야 함
}
}
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🖨️오류
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java.lang.IllegalArgumentException: org.hibernate.QueryException: illegal attempt to dereference collection [team0_.id.members] with element property reference [name] [select t.members.name from jpql.Team t]
at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:138)
at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:181)
at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:188)
at org.hibernate.internal.AbstractSharedSessionContract.createQuery(AbstractSharedSessionContract.java:725)
at org.hibernate.internal.AbstractSharedSessionContract.createQuery(AbstractSharedSessionContract.java:816)
at org.hibernate.internal.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:23)
at jpql.Main.main(Main.java:139)
Caused by: org.hibernate.QueryException: illegal attempt to dereference collection [team0_.id.members] with element property reference [name] [select t.members.name from jpql.Team t]
at org.hibernate.QueryException.generateQueryException(QueryException.java:120)
at org.hibernate.QueryException.wrapWithQueryString(QueryException.java:103)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:220)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:144)
at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:113)
at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:73)
at org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:155)
at org.hibernate.internal.AbstractSharedSessionContract.getQueryPlan(AbstractSharedSessionContract.java:604)
at org.hibernate.internal.AbstractSharedSessionContract.createQuery(AbstractSharedSessionContract.java:716)
... 3 more
Caused by: org.hibernate.QueryException: illegal attempt to dereference collection [team0_.id.members] with element property reference [name]
at org.hibernate.hql.internal.ast.tree.DotNode$1.buildIllegalCollectionDereferenceException(DotNode.java:59)
at org.hibernate.hql.internal.ast.tree.DotNode.checkLhsIsNotCollection(DotNode.java:639)
at org.hibernate.hql.internal.ast.tree.DotNode.resolve(DotNode.java:245)
at org.hibernate.hql.internal.ast.tree.FromReferenceNode.resolve(FromReferenceNode.java:114)
at org.hibernate.hql.internal.ast.tree.FromReferenceNode.resolve(FromReferenceNode.java:109)
at org.hibernate.hql.internal.ast.tree.FromReferenceNode.resolve(FromReferenceNode.java:104)
at org.hibernate.hql.internal.ast.tree.DotNode.resolveSelectExpression(DotNode.java:768)
at org.hibernate.hql.internal.ast.HqlSqlWalker.resolveSelectExpression(HqlSqlWalker.java:1065)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectExpr(HqlSqlBaseWalker.java:2319)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectExprList(HqlSqlBaseWalker.java:2256)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectClause(HqlSqlBaseWalker.java:1518)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:597)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:325)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:273)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:272)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:192)
... 9 more
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📡 원인
컬렉션 요소에 대한 직접적인 접근 시도
(Hibernate는 컬렉션에 대한 직접적인 접근을 허용하지 않음)
📰 해결 방법
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public class Main {
public static void main(String[] args) {
// 생략
try {
Team team = new Team();
team.setName("Team");
em.persist(team);
Member member = new Member();
member.setName("Member");
member.setAge(10);
member.setTeam(team);
member.setType(MemberType.ADMIN);
em.persist(member);
em.flush();
em.clear();
String query = "select m.name from Team t join t.members m ";
List<String> members = em.createQuery(query, String.class)
.getResultList();
tx.commit(); // transaction 종료 후 commit
} catch (Exception e) {
tx.rollback(); // 문제가 생길 경우, rollback 진행
e.printStackTrace();
} finally {
em.close(); // tx에 문제가 생기더라도 em 반드시 종료
}
emf.close();
// 트랜잭션 단위로 관리되는 Entity Manager는 Tx가 종료되면 close가 되어야하지만, emf는 Application 종료 시, close되어야 함
}
}
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FROM 절에서 명시적 조인을 통해 별칭을 얻으면 별칭을 통해 탐색