SELECT
tab_a.id AS position_id_fk,
tab_b.pruefziel_id_fk,
lastprf_id_fk,
lastfri_id_fk,
lastmeld_id_fk,
position_lfdnr,
pruefziel_raum_relstr,
frist_datum,
frist_art
FROM tab_a
LEFT JOIN tab_b
ON tab_b.position_id_fk = tab_a.id
AND tab_b.pruefung_id_fk = tab_a.lastprf_id_fk
LEFT JOIN tab_c
ON tab_b.pruefziel_id_fk = tab_c.id
LEFT JOIN tab_d
ON tab_b.pruefziel_id_fk = tab_d.pruefziel_id_fk
LEFT JOIN tab_e
ON tab_a.lastfri_id_fk = tab_e.id
WHERE tab_a.objekt_id_fk = 8
AND tab_a.position_status != 'Abgeschlossen'
ORDER BY frist_art ASC