za predpokladu, ze v tabulke skupina_obsah sa dane id_adresy moze nachadzat maximalne 1krat.

SELECT
ab.entry_state,
ab.address_book_id,
ab.entry_company,
case when so.id_adresy is null then null else 'check' end as checkbox_checked
FROM address_book ab
left join skupina_obsah so on so.id_adresy = ab.address_book_id
where entry_stat <> '';