https://programmers.co.kr/learn/courses/30/parts/17045
IFNULL IFNULL(A, B) A가 NULL이면 B를, 그렇지 않다면 A를 반환 SELECT ANIMAL_TYPE, IFNULL(NAME, "No name"), SEX_UPON_INTAKE FROM ANIMAL_INS ORDER BY ANIMAL_ID
IFNULL(A, B)
SELECT ANIMAL_TYPE, IFNULL(NAME, "No name"), SEX_UPON_INTAKE FROM ANIMAL_INS ORDER BY ANIMAL_ID