๐ IF ๋ฌธ
if (์กฐ๊ฑด๋ฌธ, ์ฐธ์ผ ๋ ๊ฐ, ๊ฑฐ์ง์ผ ๋ ๊ฐ)
์์ ์ฝ๋
SELECT IF(REQUIRED, "ํ์", "์ ํ") AS "์ ํ์ฌ๋ถ"
FROM SUBJECT
๐ CASE ๋ฌธ
CASE (์กฐ๊ฑด ๋๋ ๊ฐ)
WHEN ๊ฐ1 THEM ํ์๊ฐ
WHEN ๊ฐ2 THEM ํ์๊ฐ
ELSE ํ์๊ฐ
END
์์ ์ฝ๋
SELECT CASE A WHEN "1" THEN A
WHEN "2" THEN B
ELSE C END
FROM TABLE_NAME
๐ IFNULL ๋ฌธ (MYSQL ์ฌ์ฉ)
IFNULL (๊ฐ1, ๊ฐ2)
๊ฐ1์ด NULL์ด๋ฉด ๊ฐ2 ๋ฐํ, NULL์ด ์๋๋ฉด ๊ฐ1 ๋ฐํ
์์ ์ฝ๋
SELECT ISNULL(PRICE,O)
FROM BOOKS
๐ ISNULL ๋ฌธ (MYSQL ์ฌ์ฉ)
ISNULL (๊ฐ1, ๊ฐ2)
๊ฐ1์ด NULL์ด๋ฉด ๊ฐ2 ๋ฐํ, NULL์ด ์๋๋ฉด ๊ฐ1 ๋ฐํ
์์ ์ฝ๋
SELECT ISNULL(PRICE, 0)
FROM BOOKS
๐ NVL ๋ฌธ (ORACLE ์ฌ์ฉ)
NVL(๊ฐ1, ๊ฐ2)
๊ฐ1์ด NULL์ด๋ฉด ๊ฐ2 ๋ฐํ, NULL์ด ์๋๋ฉด ๊ฐ1 ๋ฐํ
์์ ์ฝ๋
SELECT NVL(PRICE, 0)
FROM BOOKS