Hibernate 和 MySQL配合的一个one-to-one 关键字教训

今天犯了一个很白痴的问题,调了一天代码. (哭ing)

Cetificate类的映射

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>
    <class name="hibernate.Certificate" table="certificate" catalog="schoolproject" lazy="true">
        <id name="id">
            <generator class="foreign">
                <param name="property">student</param>
            </generator>
        </id>
        <one-to-one 
            name="student" 
            class="hibernate.Student" 
            constrained="true">
        </one-to-one>
        <property name="describe" type="string">
            <column name="`describe`" length="100" not-null="true" />
        </property>
    </class>
</hibernate-mapping>

请注意:Certificate中的describe列的column属性name应该绝对不应配置为:describe.

describe在oracle和mysql中都是关键字.(oracle 中我最喜爱的命令之一)

应该在其前后都加上 ` 符号(是数字1左边的那个键)

Student类的映射:

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>
    <class name="hibernate.Student" table="student" catalog="schoolproject" lazy="true" >
           <id name="id" unsaved-value="null">
               <generator class="uuid.hex"></generator>
           </id>
        <many-to-one name="team" class="hibernate.Team" fetch="select" cascade="none">
            <column name="team_id" length="32"/>
        </many-to-one>
        <property name="name" type="string">
            <column name="name" length="20" />
        </property>
        <property name="cardId" type="string">
            <column name="card_id" length="20" not-null="true" unique="true" />
        </property>
        <property name="age" type="integer">
            <column name="age" />
        </property>
        <one-to-one 
            name="certificate" 
            class="hibernate.Certificate" 
            fetch="join" 
            cascade="all">
        </one-to-one>
    </class>
    <query name="queryStudentByAgeAndTeam">
        <![CDATA[
            from Student s where s.age>:age and s.team = :team
        ]]>
    </query>
</hibernate-mapping>

测试代码:

Session session = HibernateSessionFactory.getSession();
        Transaction transaction = session.beginTransaction();
        long start_time = System.nanoTime();
        try...{
            Student student = new Student();
            student.setCardId("22");
            student.setAge(22);
            student.setName("tt");
            
            Certificate certificate = new Certificate();
            certificate.setDescribe("thisisspark");

            student.setCertificate(certificate);
            certificate.setStudent(student);

            session.save(student);
            //session.save(certificate);
            transaction.commit();
        }catch(Exception e)...{
            transaction.rollback();
            e.printStackTrace();
        }finally...{
            HibernateSessionFactory.closeSession();
        }
        System.out.println("total time:" + (System.nanoTime()- start_time)/1000/1000);

 通过了,调试.