java如何进行正确的HQL连接

Question

大家好，斯塔克福勒社区

我在HQL查询中遇到问题。对于金融应用程序，我们希望基于给定的StrategyInstrument实体获取交易单实体。以下是定义的实体（省略细节，仅显示关系）

@Entity
public class Trade {
    @ManyToOne
    private Ticket ticket;

    @ManyToOne
    private Order buyOrder;

    @ManyToOne
    private Order sellOrder;
    ...
}

@Entity 
public class TradeTicket {
    private Date modifiedDateTime;
    ...
}

@Entity
public class Order {
    @OneToOne
    private StrategyInstrument strategyInstrument;
    ...
}

@Entity
public class StrategyInstrument {
    ...
}

我尝试以下查询：

String queryString = "select ticket from TradeTicket ticket"
    + " join Trade trade"
    + " join Order order"
    + " where trade.tradeTicket = ticket"
    + " and (trade.buyOrder = order or trade.sellOrder = order)"
    + " and order.strategyInstrument = :strategyInstrument"
    + " and ticket.clearingApproval.approved = true"
    + " order by ticket.modifiedDateTime";
List<TradeTicket> results = getSession()
    .createQuery(queryString)
    .setParameter("strategyInstrument", strategyInstrument)
    .list();

这将导致以下例外情况：

Caused by: org.hibernate.hql.ast.QuerySyntaxException: unexpected token: Order near line 1, column 102 [select ticket from com.mycompany.model.transactional.TradeTicket ticket join Trade trade   join Order order where trade.tradeTicket = ticket and (trade.buyOrder = order or trade.sellOrder = order) and order.strategyInstrument = :strategyInstrument and ticket.clearingApproval.approved = true order by ticket]
    at org.hibernate.hql.ast.QuerySyntaxException.convert(QuerySyntaxException.java:54)
    at org.hibernate.hql.ast.QuerySyntaxException.convert(QuerySyntaxException.java:47)
    at org.hibernate.hql.ast.ErrorCounter.throwQueryException(ErrorCounter.java:82)
    at org.hibernate.hql.ast.QueryTranslatorImpl.parse(QueryTranslatorImpl.java:284)
    at org.hibernate.hql.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:182)
    at org.hibernate.hql.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:136)
    at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:101)
    at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:80)
    at org.hibernate.engine.query.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:98)
    at org.hibernate.impl.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:156)
    at org.hibernate.impl.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:135)
    at org.hibernate.impl.SessionImpl.createQuery(SessionImpl.java:1760)

我的HQL有什么问题吗

谢谢

何塞

Answer 1

这些人是正确的，Order是保留的，但不要更改实体名称，尝试在该表的定义中使用反勾号

@Entity
@Table(name="`Order`")
public class Order {`

资料来源： Hibernate Jira

Answer 2

order是一个保留的JPQL和SQL关键字。更改实体的名称

你的语法也错了。HQL中的联接使用实体之间的关联。例如，正确的语法是

select ticket from Trade trade
join trade.ticket ticket