SELECT DISTINCT 
CONCAT(std.last_name_std,' ',std.first_name_std) as name_std,
CONCAT(lvl.name_lvl,' ',sec.name_set,' ',clg.name_clg) as course_name,
grd.first_name_grd,
grd.last_name_grd,
grd.email_grd
FROM 
student_by_course sbc
JOIN student std ON sbc.serial_std = std.serial_std
JOIN course crs ON crs.serial_crs = sbc.serial_crs
JOIN level lvl ON crs.serial_lvl = lvl.serial_lvl
JOIN section sec ON sec.serial_set = crs.serial_set
JOIN class_group clg ON clg.serial_clg = crs.serial_clg
JOIN student_guardian stg ON stg.serial_std = std.serial_std
JOIN guardian grd ON grd.serial_grd = stg.serial_grd
WHERE std.status_std = 'ACTIVE'
AND crs.serial_scy = '2'
AND sbc.status_stc = 'ACTIVE'
AND stg.status_stg = 'ACTIVE'
AND grd.status_grd = 'ACTIVE'