Question

我正在尝试使用Hibernate从Postgres DB中获取我的实体类的列表。似乎一切在配置中都是正确的，并且所有的休眠属性对我来说都很不错。

当我调用findAll方法时，我得到一个org.hibernate.exception.SQLGrammarException：无法提取ResultSet

这是我的文件：

<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <property name="dialect">org.hibernate.dialect.PostgreSQL82Dialect</property>
        <property name="connection.driver_class">org.postgresql.Driver</property>
        <property name="connection.url">jdbc:postgresql://localhost:5433/EES_Settings</property>
        <property name="connection.username">postgres</property>
        <property name="connection.password">postgres</property>
        <property name="current_session_context_class">thread</property>
        <property name="hibernate.show_sql">true</property>

        <!-- C3P0 connection pool -->
        <property name="hibernate.c3p0.timeout">600</property>
        <property name="hibernate.c3p0.maxIdleTimeExcessConnections">20</property>

        <!--  Connection testing settings -->
        <property name="hibernate.c3p0.validate">false</property>
        <property name="hibernate.c3p0.idle_test_period">30</property>
        <property name="hibernate.c3p0.automaticTestTable">conTestTable</property>

        <mapping class="com.deere.isg.easyequipmentsetup.easyequipmentsetup.entities.Configuration" resource="Mappers/Configuration.hbm.xml"/>
    </session-factory>
</hibernate-configuration>

@Id
@Column(name = "guid")
private String guid;

@Column(name = "profile_name")
private String profileName;

@Column(name= "machine_id")
private String machineId;

@Column(name= "implement_id")
private String implementId;

@Column(name= "creation_date")
@Type(type="timestamp")
private Timestamp creationDate;

@Column(name= "modification_date")
@Type(type="timestamp")
private Timestamp modificationDate;

List<Configuration> configurations = (List<Configuration>) getCurrentSession().createSQLQuery("select Cast(guid as varchar) guid, profile_name, machine_id, implement_id, creation_data, modification_date from ees_configuration").list();

预期结果是带有数据库记录的集合，实际结果是提到的异常。

Answer 1

尝试使用“条件和方法”列表来检索为该实体存储的所有记录：

List<Configuration> configurations = getCurrentSession().createCriteria(Configuration.class).list();

如果您使用ORM（在您的情况下为休眠），则不建议使用sql查询。

或者，如果您更喜欢使用Sql查询并仅提取bean的某些列，请使用addScalar将所有列绑定为所需的类型

休眠映射无法提取ResultSet

1 个答案: