๐ป Programming/SQL
์กฐ๊ฑด๋ฌธ ์ฌ์ฉ(if, case, isnull, ifnull, nvl)
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 ..