text: 
  SELECT
    true
  FROM
    lecturers
      JOIN courses ON courses.id = lecturers.course AND courses.deleted = 0
  
  WHERE
    lecturers.id = $u[id] AND
    lecturers.status = 1 AND lecturers.history = 0 AND
    lecturers.course = %d
  
  GROUP BY
    courses.id;