Hibernate 本机查询-如何从数据库中检索实体的特定列

在我的数据库中，我创建了一个带有列的表主题

id (long)
name (String)
ifActive (0 or 1)
text (very long String)

在我的网页中，我必须显示活动主题的名称列表。因此，我在xml文件中声明以下本机查询：

<sql-result-set-mapping name="SubjectResult">
    <entity-result entity-class="com.test.Subject">
        <field-result name="id" column="id"/>
        <field-result name="name" column="name"/>
        <field-result name="ifActive" column="ifActive"/>
        <field-result name="text" column="text"/>
    </entity-result>
</sql-result-set-mapping>

<entity class= "com.test.Subject" name= "Subject">
    <named-native-query name="findAllActiveSubject"
                        result-set-mapping="SubjectResult">
        <query>
            select
                *
            from 
                Subject
            where 
                ifActive = 1
        </query>
    </named-native-query>
</entity>

根本原因

com.microsoft.sqlserver.jdbc.SQLServerException: The column name id is not valid

com.microsoft.sqlserver.jdbc.SQLServerException: The column name id1_5_0_ is not valid

因此，我尝试将结果集更改为以下内容：

<sql-result-set-mapping name="SubjectResult">
    <entity-result entity-class="com.test.Subject">
        <field-result name="id" column="id"/>
        <field-result name="name" column="name"/>
        <field-result name="ifActive" column="ifActive"/>
        <field-result name="text" column="text"/>
    </entity-result>
</sql-result-set-mapping>

<entity class= "com.test.Subject" name= "Subject">
    <named-native-query name="findAllActiveSubject"
                        result-set-mapping="SubjectResult">
        <query>
            select
                name
            from 
                Subject
            where 
                ifActive = 1
        </query>
    </named-native-query>
</entity>

<sql-result-set-mapping name="SubjectResult">
    <entity-result entity-class="com.test.Subject">
        <field-result name="name" column="name"/>
    </entity-result>
</sql-result-set-mapping>

<entity class= "com.test.Subject" name= "Subject">
    <named-native-query name="findAllActiveSubject"
                        result-set-mapping="SubjectResult">
        <query>
            select
                name
            from 
                Subject
            where 
                ifActive = 1
        </query>
    </named-native-query>
</entity>

有着非常奇怪的根源

com.microsoft.sqlserver.jdbc.SQLServerException: The column name id is not valid

com.microsoft.sqlserver.jdbc.SQLServerException: The column name id1_5_0_ is not valid

所以

---

我不能只从DB中检索几个列，并仅用它们形成主题？如果Subject的其余属性为null，这对我来说没关系——我希望完全使用Subject，而不是值列表或值数组列表或类似的东西。

您可以使用带有HQL的特定构造函数

在Subject.java中创建构造函数

...
public Subject() {
}

public Subject(String name) {
    this.name = name;
}
...

select的查询应该是

select new Subject(s.name) from Subject s where s.ifActive=1