Question of plpgsql: Create trigger on the employees table. This time, if the salary is null, set the salary equal to the smallest salary in the employees table + 5000. In other words, if the table has the same three rows as above (question 1), then an insert of (20, Tracy, null) will insert Tracy and set their salary to 40000 (= min salary + 5000) (= 35000 + 5000).