錯誤當寫Hibernate的HQL

Question

我測試下面的HQL，但得到一個錯誤

String SQL="From Bid bid where bid.Auction.AuctionId=3655" 

類投標映射文件：

<?xml version="1.0"?> 
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> 
<!-- Generated Jan 19, 2011 5:25:35 AM by Hibernate Tools 3.4.0.Beta1 --> 
<hibernate-mapping> 
    <class name="com.BiddingSystem.Models.Bid" table="BID"> 
     <id name="BidId" type="long"> 
      <column name="BIDID" /> 
      <generator class="native" /> 
     </id> 
     <property name="BidAmount" type="long"> 
      <column name="BIDAMOUNT" /> 
     </property> 
     <many-to-one name="User" class="com.BiddingSystem.Models.Users" fetch="join"> 
      <column name="UserId" /> 
     </many-to-one> 
     <many-to-one name="auction" class="com.BiddingSystem.Models.Auction" fetch="join" lazy="false"> 
      <column name="AuctionId" /> 
     </many-to-one> 
     <property name="TimePosted" type="java.util.Date" access="field"> 
      <column name="TIMEPOSTED" /> 
     </property> 
    </class> 
</hibernate-mapping> 

拍賣映射文件：

<?xml version="1.0"?> 
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> 
<!-- Generated Dec 28, 2010 9:14:12 PM by Hibernate Tools 3.4.0.Beta1 --> 
<hibernate-mapping> 
    <class name="com.BiddingSystem.Models.Auction" table="AUCTION"> 
     <id name="AuctionId" type="long"> 
      <column name="AUCTIONID" /> 
      <generator class="native" /> 
     </id> 
     <property name="StartTime" type="java.util.Date"> 
      <column name="STARTTIME" /> 
     </property> 
     <property name="EndTime" type="java.util.Date"> 
      <column name="ENDTIME" /> 
     </property> 
     <property name="DatePlaced" type="java.util.Date"> 
      <column name="DatePlaced" /> 
     </property> 
     <property name="StartingBid" type="long"> 
      <column name="STARTINGBID" /> 
     </property> 
     <property name="MinIncrement" type="long"> 
      <column name="MININCREMENT" /> 
     </property> 
     <many-to-one name="CurrentItem" class="com.BiddingSystem.Models.Item" fetch="join" not-null="true" cascade="all" unique="true" lazy="false"> 
      <column name="CURRENTITEM" /> 
     </many-to-one> 

     <property name="AuctionStatus" type="java.lang.String"> 
      <column name="AUCTIONSTATUS" /> 
     </property> 
     <property name="BestBid" type="long"> 
      <column name="BESTBID" /> 
     </property> 
     <many-to-one name="User" class="com.BiddingSystem.Models.Users" fetch="join"> 
      <column name="UserId" /> 
     </many-to-one> 
    </class> 
</hibernate-mapping> 

錯誤：

Caused by: org.hibernate.QueryException: could not resolve property: Auction of: com.BiddingSystem.Models.Bid [From com.BiddingSystem.Models.Bid bid where bid.Auction.AuctionId=3655 and bid.User.UserId=3657] 
    at org.hibernate.persister.entity.AbstractPropertyMapping.propertyException(AbstractPropertyMapping.java:81) 
    at org.hibernate.persister.entity.AbstractPropertyMapping.toType(AbstractPropertyMapping.java:75) 
    at org.hibernate.persister.entity.AbstractEntityPersister.toType(AbstractEntityPersister.java:1449) 
    at org.hibernate.hql.ast.tree.FromElementType.getPropertyType(FromElementType.java:315) 
    at org.hibernate.hql.ast.tree.FromElement.getPropertyType(FromElement.java:487) 
    at org.hibernate.hql.ast.tree.DotNode.getDataType(DotNode.java:611) 
    at org.hibernate.hql.ast.tree.DotNode.prepareLhs(DotNode.java:263) 
    at org.hibernate.hql.ast.tree.DotNode.resolve(DotNode.java:210) 
    at org.hibernate.hql.ast.tree.DotNode.resolveFirstChild(DotNode.java:175) 
    at org.hibernate.hql.ast.HqlSqlWalker.lookupProperty(HqlSqlWalker.java:571) 
    at org.hibernate.hql.antlr.HqlSqlBaseWalker.addrExpr(HqlSqlBaseWalker.java:4774) 
    at org.hibernate.hql.antlr.HqlSqlBaseWalker.expr(HqlSqlBaseWalker.java:1326) 
    at org.hibernate.hql.antlr.HqlSqlBaseWalker.exprOrSubquery(HqlSqlBaseWalker.java:4471) 
    at org.hibernate.hql.antlr.HqlSqlBaseWalker.comparisonExpr(HqlSqlBaseWalker.java:3944) 
    at org.hibernate.hql.antlr.HqlSqlBaseWalker.logicalExpr(HqlSqlBaseWalker.java:2047) 
    at org.hibernate.hql.antlr.HqlSqlBaseWalker.logicalExpr(HqlSqlBaseWalker.java:1972) 
    at org.hibernate.hql.antlr.HqlSqlBaseWalker.whereClause(HqlSqlBaseWalker.java:831) 
    at org.hibernate.hql.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:617) 
    at org.hibernate.hql.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:301) 
    at org.hibernate.hql.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:244) 
    at org.hibernate.hql.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:254) 
    at org.hibernate.hql.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:185) 
    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:124) 
    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:1770) 
    at com.BiddingSystem.server.ServiceImpl.getBid(ServiceImpl.java:1463) 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) 
    at java.lang.reflect.Method.invoke(Method.java:597) 
    at net.sf.gilead.gwt.PersistentRemoteService.processCall(PersistentRemoteService.java:174) 

Answer 1

我敢打賭，這將工作

String SQL="From Bid bid where bid.auction.auctionId=3655" 

屬性都應該總是在Java小寫字符開始。

Answer 2

根據您Bid映射文件，你的SQL應該是這樣的： -

String SQL="From Bid bid where bid.auction.AuctionId=3655" 

但嚴重的是，你的駱駝外殼在豆類真的搞砸了。在bean 屬性名應當小字母開頭第一（例如：auctionId，auction，timePosted等）。