jpa在数据库中看不到表

Question

当我执行时

@NamedQuery(name = "GroupsHasStudent.findByGroupsidGroups", query = "从 GroupsHasStudent g 中选择 g，其中 g.groupsHasStudentPK.groupsidGroups = :groupsidGroups"),

的 组有学生 实体，结果生成正确。但另一个 NativeQuery

getEntityManager().
            createNativeQuery(
            "SELECT d.idDiscipline, d.name, gy.idGroupsYear, gy.year, g.idGroups "
            + "FROM Discipline d, Groupsyear gy, Groups g, GroupsHasStudent ghs "
            + "WHERE ghs.groupsHasStudentPK.groupsidGroups=2").
            getResultList();

抛出异常

Internal Exception:
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException:
Table 'mydb.groupshasstudent' doesn't exist

实际上我在数据库中没有这样的表，但正确的名称是 *groups_has_student* ，它在 @Table 中指定：

（我的实体：）

@Entity
@Table(name = "groups_has_student")
@XmlRootElement
@NamedQueries({
    @NamedQuery(name = "GroupsHasStudent.findAll", query = "SELECT g FROM GroupsHasStudent g"),
    @NamedQuery(name = "GroupsHasStudent.findByGroupsidGroups", query = "SELECT g FROM GroupsHasStudent g WHERE g.groupsHasStudentPK.groupsidGroups = :groupsidGroups"),
    @NamedQuery(name = "GroupsHasStudent.findByStudentUserslogin", query = "SELECT g FROM GroupsHasStudent g WHERE g.groupsHasStudentPK.studentUserslogin = :studentUserslogin")})
public class GroupsHasStudent implements Serializable {
    private static final long serialVersionUID = 1L;
    @EmbeddedId
    protected GroupsHasStudentPK groupsHasStudentPK;

    public GroupsHasStudent() {
    }

即使我将 mysql 中的表重命名为 组有学生 还有另一个异常

Unknown column 'ghs.groupsHasStudentPK.studentUserslogin' in 'where clause'

Іце сумно..

Answer 1

它不是本机（SQL）查询，而是 JPQL 查询，因此您应该使用 createQuery() 代替 createNativeQuery().