SELECT * FROM ISA_CTRL.PORTAL_SESS_KONTR psk
INNER JOIN isa_ctrl.portal_sess_kontr_prep pskp ON pskp.s_portal_sess_kontr=psk.idz
WHERE psk.uch_god='2017/2018'
AND psk.s_grupstu=6426 AND pskp.lichkr=29769