Finding the entity with the most relationships in JPQL

Question

I have a teacher entity, which has a ManytoMany with semesters.

So many teachers can have many semesters. I'm trying to write a JPQL query, where I can get the teacher, that has the most amount of semesters.

  public TeacherEntity teacherWithMostSemesters(){
    EntityManager em = emf.createEntityManager();
    em.createQuery("SELECT te from TeacherEntity te").getResultList();
    return null;
}

My issue is that I have generated my database from a database scheme,

and it has created a weird entity with the FK for both the teacher's table and the semester table

package com.tvestergaard.start.data.entities;

import javax.persistence.*;
import java.util.Objects;

@Entity
@Table(name = "teacher_semester", schema = "student", catalog = "")
@IdClass(TeacherSemesterEntityPK.class)
public class TeacherSemesterEntity {
    private long teachingId;
    private long teachersId;

    @Id
    @Column(name = "teaching_ID")
    public long getTeachingId() {
        return teachingId;
    }

    public void setTeachingId(long teachingId) {
        this.teachingId = teachingId;
    }

    @Id
    @Column(name = "teachers_ID")
    public long getTeachersId() {
        return teachersId;
    }

    public void setTeachersId(long teachersId) {
        this.teachersId = teachersId;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        TeacherSemesterEntity that = (TeacherSemesterEntity) o;
        return teachingId == that.teachingId &&
                teachersId == that.teachersId;
    }

    @Override
    public int hashCode() {
        return Objects.hash(teachingId, teachersId);
    }
}

It should have created a relationship between the two, but instead, it generated a table of the table with the two foreign keys...

How can I fix this, and make a JPQL query, who finds the teacher with the most semesters taught?