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ํ”„๋กœ๊ทธ๋ž˜๋จธ์Šค - NULL ์ฒ˜๋ฆฌํ•˜๊ธฐ, MySQL

by Janger 2021. 11. 22.
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https://programmers.co.kr/learn/courses/30/lessons/59410

 

์ฝ”๋”ฉํ…Œ์ŠคํŠธ ์—ฐ์Šต - NULL ์ฒ˜๋ฆฌํ•˜๊ธฐ

ANIMAL_INS ํ…Œ์ด๋ธ”์€ ๋™๋ฌผ ๋ณดํ˜ธ์†Œ์— ๋“ค์–ด์˜จ ๋™๋ฌผ์˜ ์ •๋ณด๋ฅผ ๋‹ด์€ ํ…Œ์ด๋ธ”์ž…๋‹ˆ๋‹ค. ANIMAL_INS ํ…Œ์ด๋ธ” ๊ตฌ์กฐ๋Š” ๋‹ค์Œ๊ณผ ๊ฐ™์œผ๋ฉฐ, ANIMAL_ID, ANIMAL_TYPE, DATETIME, INTAKE_CONDITION, NAME, SEX_UPON_INTAKE๋Š” ๊ฐ๊ฐ ๋™๋ฌผ์˜ ์•„์ด๋””

programmers.co.kr

 

SELECT ANIMAL_TYPE, IFNULL(NAME, "No name") as NAME, SEX_UPON_INTAKE
FROM ANIMAL_INS
ORDER BY ANIMAL_ID ASC

 

IFNULL(NAME, "No name") as NAME <- ๋งŒ์•ฝ NULL์ธ ๊ฒฝ์šฐ์—” No name ์ถœ๋ ฅ ์•„๋‹ˆ๋ฉด NAME์„ ๊ทธ๋Œ€๋กœ ์ถœ๋ ฅ

 

์ฐธ์กฐ: 

https://cyller.tistory.com/59

 

MySQL ์ œ์–ด ํ•จ์ˆ˜ (CASE, IF, IFNULL, NULLIF)

1. CASE value WHEN [compare_value] THEN result [WHEN [compare_value] THEN result ...] [ELSE result] END    CASE WHEN [condition] THEN result [WHEN [condition] THEN result ...] [ELSE result] END 2...

cyller.tistory.com

 

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