text: select 
     s.id, s.name, s.age, sc.score, c.course_name
  from 
     t_student s,
     t_course c,
     t_student_course sc
  where
     s.id = sc.student_id
  and
     c.id = sc.course_id
  #if($entity.name)
    and s.name like :entity.name
  #end
  
  #if($entity.age)
    and s.age = :entity.age
  #end