jpa在db中看不到表

Question

When I execute

@NamedQuery(name = "GroupsHasStudent.findByGroupsidGroups", query = "SELECT g FROM GroupsHasStudent g WHERE g.groupsHasStudentPK.groupsidGroups = :groupsidGroups"),

of GroupsHasStudent entity, the result is generated correct. But another 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();

throws the Exception

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

Actually I do don't have such table in db, but the correct name is *groups_has_student* which is specified in @Table:

(My entity:)

@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() {
    }

And even when I rename table in mysql to groupshasstudent there is another Exception

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

І це сумно..

Answer 1

这不是本机（SQL）查询，而是JPQL查询，因此您应该使用createQuery()而不是createNativeQuery() 。