several SQLs

someQueries.sql

1) SELECT * FROM category c WHERE c.parent_category_id IS NULL AND name LIKE 'авто%';

2) SELECT * FROM category c1 WHERE (SELECT COUNT(c2.id) FROM category c2 WHERE c2.parent_category_id = c1.id
 AND c2.id NOT IN (SELECT parent_category_id FROM category c3 WHERE parent_category_id IS NOT NULL)
) BETWEEN 1 AND 3;

3)  
  SELECT * FROM category с1 LEFT JOIN category с2 ON с1.id = с2.parent_category_id WHERE с2.id IS NULL
or:
  SELECT * FROM category AS c1 WHERE NOT EXISTS (SELECT id FROM category AS c2 WHERE c1.id = c2.parent_category_id);