hibernate 多对多关系如何通过hql查????

/////实体1

@ManyToMany(fetch = FetchType.EAGER)
@JoinTable(
        name="po_publicOpinion_unitCounties",
        joinColumns=
        @JoinColumn(name="publicOpinion_id", referencedColumnName="id"),
        inverseJoinColumns=
        @JoinColumn(name="unitCounties_id", referencedColumnName="id")
)
private List<UnitCounties> unitCounties;  //////join的字段



////////////实体2

@ManyToMany(mappedBy = "unitCounties",fetch = FetchType.EAGER)
@JsonIgnore
private List<PublicOpinion> publicOpinions;




hql查询
        "SELECT count(o) from PublicOpinion  o  join o.unitCounties u  where  u.id=1";