public void removeEmployeeSkill(Employee employee, Skill skill) {
   open();
   ContentValues cv = new ContentValues();
   cv.put(EMPLOYEE_ID, employee.getId());
   cv.put(SKILL_ID, skill.getId());
   myDatabase.delete(
       EMPLOYEE_SKILL_TABLE,
       EMPLOYEE_ID + " =? AND " + SKILL_ID + " =?",
       new String[] {Integer.toString(employee.getId()), Integer.toString(skill.getId())});
   close();
 }
 public void addEmployeeSkill(Employee employee, Skill skill) {
   open();
   ContentValues cv = new ContentValues();
   cv.put(EMPLOYEE_ID, employee.getId());
   cv.put(SKILL_ID, skill.getId());
   myDatabase.insert(EMPLOYEE_SKILL_TABLE, null, cv);
   close();
 }