Java hbm.xml一列的多索引

比如说,

<?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 package="com.sql.index">
    <class name="User">
        <id name="id" type="long">
            <generator class="native" />
        </id>
        <property name="firstName" type="string" index="IDX_FIRST_NAME" />
        <property name="lastName" type="string" />
        <property name="address" type="string" />
        <property name="field_1" type="long" />
        <property name="field_2" type="long" />
    </class>
</hibernate-mapping>

field_1

和

field_2

将为其自身设置两个索引

---

我引用了，似乎

索引

字段只能由

一列

分配

---

附言 这个项目有点旧，由很多人维护，所以我不能使用注释语法添加

索引
 我找到了那本书，试了一下

<?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 package="com.sql.index">
    <class name="User">
        <id name="id" type="long">
            <generator class="native" />
        </id>
        <property name="firstName" type="string" index="IDX_FIRST_NAME" />
        <property name="lastName" type="string" />
        <property name="address" type="string" />
        <property name="field_1" type="long" index="idx_2"/>
        <property name="field_2" type="long" index="idx_3"/>
    </class>
    <database-object>
        <create>
            CREATE INDEX idx_1 ON User (field_1, field_2)
        </create>
        <drop></drop>
    </database-object>
</hibernate-mapping>

您第一次使用逗号的方法是正确的。尝试之后，它会起作用。非常感谢。
<?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 package="com.sql.index">
    <class name="User">
        <id name="id" type="long">
            <generator class="native" />
        </id>
        <property name="firstName" type="string" index="IDX_FIRST_NAME" />
        <property name="lastName" type="string" />
        <property name="address" type="string" />
        <property name="field_1" type="long" index="idx_2"/>
        <property name="field_2" type="long" index="idx_3"/>
    </class>
    <database-object>
        <create>
            CREATE INDEX idx_1 ON User (field_1, field_2)
        </create>
        <drop></drop>
    </database-object>
</hibernate-mapping>

<properties name="uk1" unique="true">
        <property name="username" .../>
        <many-to-one name="client" .../>
</properties>

<properties name="uk2" unique="true">
        <property name="email" .../>
        <many-to-one name="client" update="false" insert="false" .../>
</properties>