๊ด€๋ฆฌ ๋ฉ”๋‰ด

Jerry

[ํ”„๋กœ๊ทธ๋ž˜๋จธ์Šค/SQL ๊ณ ๋“์  Kit] ์กฐ๊ฑด์— ๋งž๋Š” ์‚ฌ์šฉ์ž์™€ ์ด ๊ฑฐ๋ž˜๊ธˆ์•ก ์กฐํšŒํ•˜๊ธฐ ๋ณธ๋ฌธ

Problem Solving/SQL ๋ฌธ์ œ ํ’€๊ธฐ

[ํ”„๋กœ๊ทธ๋ž˜๋จธ์Šค/SQL ๊ณ ๋“์  Kit] ์กฐ๊ฑด์— ๋งž๋Š” ์‚ฌ์šฉ์ž์™€ ์ด ๊ฑฐ๋ž˜๊ธˆ์•ก ์กฐํšŒํ•˜๊ธฐ

juicyjerry 2023. 11. 6. 16:20
๋ฐ˜์‘ํ˜•

๐Ÿ’ช๋ฌธ์ œ
USED_GOODS_BOARD์™€ USED_GOODS_USER ํ…Œ์ด๋ธ”์—์„œ ์™„๋ฃŒ๋œ ์ค‘๊ณ  ๊ฑฐ๋ž˜์˜ ์ด๊ธˆ์•ก์ด 70๋งŒ ์› ์ด์ƒ์ธ ์‚ฌ๋žŒ์˜ ํšŒ์› ID, ๋‹‰๋„ค์ž„, ์ด๊ฑฐ๋ž˜๊ธˆ์•ก์„ ์กฐํšŒํ•˜๋Š” SQL๋ฌธ์„ ์ž‘์„ฑํ•ด์ฃผ์„ธ์š”. ๊ฒฐ๊ณผ๋Š” ์ด๊ฑฐ๋ž˜๊ธˆ์•ก์„ ๊ธฐ์ค€์œผ๋กœ ์˜ค๋ฆ„์ฐจ์ˆœ ์ •๋ ฌํ•ด์ฃผ์„ธ์š”.

 

 

ํ”„๋กœ๊ทธ๋ž˜๋จธ์Šค

์ฝ”๋“œ ์ค‘์‹ฌ์˜ ๊ฐœ๋ฐœ์ž ์ฑ„์šฉ. ์Šคํƒ ๊ธฐ๋ฐ˜์˜ ํฌ์ง€์…˜ ๋งค์นญ. ํ”„๋กœ๊ทธ๋ž˜๋จธ์Šค์˜ ๊ฐœ๋ฐœ์ž ๋งž์ถคํ˜• ํ”„๋กœํ•„์„ ๋“ฑ๋กํ•˜๊ณ , ๋‚˜์™€ ๊ธฐ์ˆ  ๊ถํ•ฉ์ด ์ž˜ ๋งž๋Š” ๊ธฐ์—…๋“ค์„ ๋งค์นญ ๋ฐ›์œผ์„ธ์š”.

programmers.co.kr

 

 

 

๐Ÿ’ช ๋‚˜์˜ ์ •๋‹ต

SELECT B.USER_ID, B.NICKNAME, SUM(A.PRICE) AS 'TOTAL_SALES'
FROM USED_GOODS_BOARD AS A
INNER JOIN USED_GOODS_USER  AS B
ON A.WRITER_ID = B.USER_ID 
WHERE A.STATUS = 'DONE'
GROUP BY B.USER_ID

# HAVING SUM(A.PRICE) AS 'TOTAL_SALES' >= 700000 # ์•ˆ ๋จ
# HAVING 'TOTAL_SALES' >= 700000 # ์•ˆ ๋จ
# HAVING 3 >= 700000 # ์•ˆ ๋จ
# HAVING SUM(A.PRICE) >= 700000 # ๋จ
HAVING TOTAL_SALES >= 700000 # ๋จ

# ORDER BY SUM(A.PRICE) AS 'TOTAL_SALES' ASC; # ์•ˆ ๋จ
# ORDER BY 'TOTAL_SALES' ASC; # ์•ˆ ๋จ
# ORDER BY SUM(A.PRICE) ASC; # ๋จ
# ORDER BY 3 ASC; # ๋จ
ORDER BY TOTAL_SALES ASC; # ๋จ

 

 

 

๐Ÿ’ช ๋‹ค๋ฅธ ์ •๋‹ต

- ...

 

 

๐Ÿ’ช ๋ฐฐ์šด ์ 

- WHERE์ ˆ๊ณผ HAVING ์˜ ์ฐจ์ด์— ๋Œ€ํ•ด ์•Œ๊ฒŒ ๋˜์—ˆ๋‹ค.

> WHERE์ ˆ์€ ๋ ˆ์ฝ”๋“œ๋ฅผ ํƒ€๊นƒ์„ ํ•˜์ง€๋งŒ HAVING์€ GROUP BY๋ฅผ ํ†ตํ•ด ๊ทธ๋ฃนํ™”๋œ ๊ฐ’์„ ํƒ€๊นƒํ•ฉ๋‹ˆ๋‹ค.

 

- HAVING์ ˆ์—์„œ๋Š” ์ปฌ๋Ÿผ ์ˆœ์„œ(์ˆซ์ž)๋ฅผ ์ด์šฉํ•ด์„œ ์‚ฌ์šฉํ•  ์ˆ˜ ์—†๋‹ค.

- HAVING์ ˆ์—์„œ๋Š” Alias๋กœ ์ง€์ •ํ•œ ๊ฐ’์„ ์‚ฌ์šฉํ•  ์ˆ˜ ์žˆ๋‹ค. ๋‹ค๋งŒ, Alias์— ๋”ฐ์˜ดํ‘œ๋ฅผ ๋ถ™์ด๋ฉด ์›ํ•˜๋Š” ๋Œ€๋กœ ๋™์ž‘ ๋˜์ง€ ์•Š๋Š”๋‹ค.

 

- ORDER BY์ ˆ์—์„œ๋Š” ์ปฌ๋Ÿผ ์ˆœ์„œ(์ˆซ์ž)๋ฅผ ์ด์šฉํ•ด์„œ ์‚ฌ์šฉํ•  ์ˆ˜ ์žˆ๋‹ค.

- ORDER BY์ ˆ์—์„œ๋Š” Alias๋กœ ์ง€์ •ํ•œ ๊ฐ’์„ ์‚ฌ์šฉํ•  ์ˆ˜ ์žˆ๋‹ค. ๋‹ค๋งŒ, Alias์— ๋”ฐ์˜ดํ‘œ๋ฅผ ๋ถ™์ด๋ฉด ์›ํ•˜๋Š” ๋Œ€๋กœ ๋™์ž‘ ๋˜์ง€ ์•Š๋Š”๋‹ค.

 

 

 

๐Ÿ’ช ๋งˆ์น˜๋ฉด์„œ

๋‹ค์Œ์—๋Š” ๋‹ค๋ฅธ ๋ฌธ์ œ๋กœ ์ฐพ์•„๋ต™๊ฒ ์Šต๋‹ˆ๋‹ค!

์•ˆ๋…• :))

 

 

 

 

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