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Data Base/MySQL27

MySQL 21λ²ˆμ§Έμˆ˜μ—… ​ 11-10) λ“±λ‘κΈˆ 총앑이 20191005번과 λ™μΌν•œ ν•™μƒμ˜ ν•™λ²ˆκ³Ό λ“±λ‘κΈˆμ„ 좜λ ₯ν•˜λΌ. A) mysql> select stu_no, sum(fee_total) -> from fee -> group by stu_no -> having sum(fee_total) = all -> (select sum(fee_total) from fee where stu_no = '20191005'); ​ ​ 11-11) μˆ˜κ°•μ‹ μ²­ν•œ 학생이 등둝을 ν•˜μ˜€λ‹€λ©΄ 학생이 λ‚©μž…ν•œ ν•™λ²ˆκ³Ό λ“±λ‘κΈˆ 총앑을 좜λ ₯ν•˜λΌ.​ A) mysql> select stu_no, sum(fee_total) -> from fee -> group by stu_no -> having stu_no in -> (select stu_no from attend wher.. 2021. 2. 9.
MySQL 20λ²ˆμ§Έμˆ˜μ—… β–Ά GROUP BY와 HAVING ​​ 1. μ—΄μ˜ 그룹화​ ​ 예제 11-1) STUDENT ν…Œμ΄λΈ”μ— μžˆλŠ” ν•™μƒμ˜ μž…ν•™λ…„λ„λ³„ 그룹을 좜λ ₯ν•˜λΌ. A) mysql> select substring(stu_no, 1, 4) -> from student -> group by substring(stu_no, 1, 4); ​ ​ 예제 11-2) 각 μž…ν•™λ…„λ„λ³„ 총 학생 수λ₯Ό 좜λ ₯ν•˜λΌ. A) mysql> select substring(stu_no, 1, 4), count(*) -> from student -> group by substring(stu_no, 1, 4); ​ ​ 예제 11-3) λ“±λ‘ν•œ 학생에 λŒ€ν•˜μ—¬ ν•™λ²ˆ, λ“±λ‘νšŸμˆ˜, 각 학생이 받은 μž₯ν•™κΈˆμ˜ 전체 합을 좜λ ₯ν•˜λΌ. A) mysql> select stu_no,.. 2021. 2. 9.
MySQL 19λ²ˆμ§Έμˆ˜μ—… β–Ά ν†΅κ³„ν•¨μˆ˜ ​ 1. λͺ¨λ“  μ—΄μ˜ 선택(*)​ mysql> select * from circle;​ ​ ​ 2. SELECT절의 μˆ˜μ‹ μ§€κΈˆκΉŒμ§€ SELECT절의 λŒ€λΆ€λΆ„μ˜ μ˜ˆμ œλŠ” μ—΄μ˜ μ΄λ¦„λ§Œμ„ μ§€μ •ν–ˆμ§€λ§Œ μˆ˜μ‹μ—λŠ” λ¦¬ν„°λŸ΄, 계산 λ˜λŠ” 슀칼라 ν•¨μˆ˜λ₯Ό μ‚¬μš©ν•  μˆ˜λ„ μžˆλ‹€. ​ ​ 예제 10-1) 2019년에 λ“±λ‘ν•œ 학생에 λŒ€ν•œ ν•™λ²ˆ, 년도, ν•™κΈ°, μž₯ν•™κΈˆμ•‘, 납뢀총앑(λ“±λ‘κΈˆ-μž₯ν•™κΈˆ), λ‚©λΆ€κΈˆλΉ„μœ¨(납뢀총앑/λ“±λ‘κΈˆ*100), '%'을 좜λ ₯ν•˜μ‹œμ˜€. A) mysql> select stu_no, fee_year, fee_term, fee_total, jang_total, -> fee_pay "납뢀총앑", fee_pay/fee_total*100 "λ‚©λΆ€κΈˆλΉ„μœ¨", '%' -> from fee -> where fee_year = 2.. 2021. 2. 8.
MySQL 18λ²ˆμ§Έμˆ˜μ—… 9-11) μž₯ν•™κΈˆ μˆ˜λ Ήμ΄μ•‘μ΄ 500,000μ›μ—μ„œ 2,000,000원 사이에 ν¬ν•¨λ˜μ§€ μ•ŠλŠ” 각 ν•™μƒμ˜ ν•™λ²ˆμ„ 좜λ ₯ν•˜λΌ. A) mysql> select stu_no -> from fee -> group by stu_no -> having not(sum(ifnull(jang_total, 0)) between 500000 and 2000000); ​ ​ 9-12) μž…ν•™λ…„λ„κ°€ 2002λ…„λΆ€ν„° 2006λ…„κΉŒμ§€ μž…ν•™ν•œ ν•™μƒμ˜ ν•™λ²ˆκ³Ό μž…ν•™λ…„λ„λ₯Ό 좜λ ₯ν•˜λΌ.​ A) mysql> select stu_no, fee_year -> from fee -> where fee_div='Y' and fee_enter is not null -> and fee_year between 2012 and 2018; ​ ​ 9-13) μΆœμƒλ…„λ„κ°€ 19.. 2021. 2. 8.
MySQL 17λ²ˆμ§Έμˆ˜μ—… β–Ά NULL μ—°μ‚°μž ​ 예제 9-17) νœ΄λŒ€ν°μ„ κ°€μ§€κ³ μžˆλŠ” ν•™μƒμ˜ ν•™λ²ˆκ³Ό 이름, νœ΄λŒ€ν° 번호λ₯Ό λ‚˜νƒ€λ‚΄μ–΄λΌ. A) mysql> select stu_no, stu_name, mobile -> from student -> where mobile is not null; ​​ ​ 예제 9-18) νœ΄λŒ€ν°μ„ 가지고 μžˆμ§€ μ•Šμ€ ν•™μƒμ˜ ν•™λ²ˆκ³Ό 이름, νœ΄λŒ€ν° λ²ˆν˜Έκ°€ NULL인 κ²½μš°μ—λŠ” "νœ΄λŒ€ν° μ—†μŒ"을 λ‚˜νƒ€λ‚΄μ–΄λΌ. A) mysql> select stu_no, stu_name, ifnull(mobile, 'νœ΄λŒ€ν°μ—†μŒ') -> from student -> where mobile is null; ​ ​​ 예제 9-19) ν•™μƒμ˜ νœ΄λŒ€ν°λ²ˆν˜Έ(MOBILE)κ°€ 010이 μ•„λ‹Œ λͺ¨λ“  ν•™μƒμ˜ ν•™λ²ˆκ³Ό 이름, νœ΄λŒ€ν°λ²ˆν˜Έλ₯Ό 좜λ ₯ν•˜λΌ. (단, 휴.. 2021. 2. 8.
MySQL 16λ²ˆμ§Έμˆ˜μ—… 8-3) 각 학생에 λŒ€ν•˜μ—¬ μˆ˜κ°•μ‹ μ²­ κ³Όλͺ©μ½”λ“œ, μˆ˜κ°•ν•™μ μ„ λ‚˜νƒ€λ‚΄μ–΄λΌ. A) mysql> select stu_no, sub_code, att_point from attend where att_div = 'y'; ​ ​ ​ 8-4) μž₯ν•™κΈˆμ„ 받은 ν•™μƒμ˜ ν•™λ²ˆκ³Ό 이름을 λ‚˜νƒ€λ‚΄μ–΄λΌ. A) mysql> select distinct​ s.stu_no, stu_name β†’ from student s, fee f​ β†’ where s.stu_no = f.stu​_no and ifnull(jang_total, 0) > 0; ​ ​ ​ β–Ά SELECT λͺ…λ Ήλ¬Έ : WHERE절 ​ 1. 관계 μ—°μ‚°μžλ₯Ό μ‚¬μš©ν•˜λŠ” 쑰건 ​​ 예제 9-1) 성별이 μ—¬μžμΈ ν•™μƒμ˜ ν•™λ²ˆκ³Ό 이름, 성별, 생년월일을 좜λ ₯ν•˜λΌ. A) mysql> select.. 2021. 2. 8.
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