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MySQL

MySQL

MySQL은 오픈 소스 관계형 데이터베이스 관리 시스템(RDBMS)입니다.

MySQL은 다중 사용자, 다중 스레드 RDBMS로서, 데이터의 안정성과 보안성을 제공합니다. MySQL은 대부분의 운영 체제에서 작동하며, 웹 애플리케이션 개발, 데이터 분석, 빅 데이터, 클라우드 기반 애플리케이션 등에 많이 사용됩니다.

MySQL은 SQL(Structured Query Language)을 사용하여 데이터를 관리합니다. SQL은 데이터베이스에 저장된 데이터를 조작하기 위한 표준적인 언어로서, 데이터를 검색, 삽입, 업데이트, 삭제하는데 사용됩니다.

MySQL은 이러한 SQL 문을 이용하여 데이터를 쿼리하고, 데이터의 무결성을 유지하며, 데이터베이스를 관리합니다. MySQL은 사용이 간편하며, 대용량 데이터베이스를 처리할 수 있는 고성능 기능을 제공합니다. 또한, 오픈 소스로서, 다양한 개발자들이 지속적으로 개발 및 유지보수하고 있어, 사용자들이 다양한 문제들을 해결할 수 있는 방법을 제공합니다.

MySQL은 PHP 스크립트 언어와 상호 연동이 잘 되면서 오픈소스로 개발된 무료 프로그램 입니다. 그래서 홈페이지나 쇼핑몰(워드프레스, Cafe24, 그누보드, 제로보드)등 가장 일반적으로 사용하고 있습니다.

MySQL 설치

MAMP란 웹사이트를 개발할 때 쓰이는 기술 스택인 macOS, Apache, MySQL, PHP의 약어이자 솔루션 스택이다. https://www.mamp.info/en/downloads/

php 정보 확인

phpInfo()
정보파일 수정 위치 : Loaded Configuration File C:\MAMP\conf\php8.0.1\php.ini
에러 표시 : display_errors = on
캐시 설정 : opcache.enable = 0
PHP 관리자 페이지 : http://localhost/phpMyAdmin/

MySQL 실행

윈도우 : cd c:\/MAMP/bin/mysql/bin
로그인 : mysql -uroot -proot

맥 : cd /Applications/MAMP/Library/bin
로그인 : ./mysql -uroot -proot
Welcome to the MySQL monitor.  Commands end with ; or \g.
    Your MySQL connection id is 4
    Server version: 5.7.24 MySQL Community Server (GPL)
    
    Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
    
    Oracle is a registered trademark of Oracle Corporation and/or its
    affiliates. Other names may be trademarks of their respective
    owners.
    
    Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

데이터베이스

데이터베이스 보기

show databases;
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.01 sec)

데이터베이스 만들기

create database 데이터베이스이름;
mysql> create database sample01;
Query OK, 1 row affected (0.00 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sample01           |
| sys                |
+--------------------+
5 rows in set (0.00 sec)

데이터베이스 사용

use 데이터베이스이름;
mysql> use sample01;
Database changed

데이터베이스 삭제

drop database 데이터베이스이름;
mysql> drop database sample01;
Query OK, 0 rows affected (0.02 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.00 sec)

테이블

테이블 만들기
create table 테이블이름;
create table members (
    memberID int(10) unsigned auto_increment,
    youEmail varchar(40) NOT NULL,
    youName varchar(10) NOT NULL,
    youPass varchar(20) NOT NULL,
    youBirth int(10) NOT NULL,
    youAge int(5) NOT NULL,
    regTime int(30) NOT NULL,
    PRIMARY KEY (MemberID)
) charset=utf8;

create table reviews (
    reviewID int(10) unsigned auto_increment,
    memberID int(10) unsigned,
    youText tinytext NOT NULL,
    regTime int(30) NOT NULL,
    PRIMARY KEY (reviewID)
) charset=utf8;
--------------------입력후 cmd----------------------

mysql> create table member (
    ->     memberID int(10) unsigned auto_increment,
    ->     youEmail varchar(40) NOT NULL,
    ->     youName varchar(10) NOT NULL,
    ->     youPass varchar(20) NOT NULL,
    ->     youBirth int(10) NOT NULL,
    ->     youAge int(5) NOT NULL,
    ->     regTime int(30) NOT NULL,
    ->     PRIMARY KEY (MemberID)
    -> ) charset=utf8;
Query OK, 0 rows affected (0.03 sec)
테이블 전체보기
show tables;
mysql> show tables;
+--------------------+
| Tables_in_sample01 |
+--------------------+
| member             |
+--------------------+
1 row in set (0.00 sec)
테이블 보기
desc 테이블이름;
mysql> desc member;
+------------+------------------+------+-----+---------+----------------+
| Field      | Type             | Null | Key | Default | Extra          |
+------------+------------------+------+-----+---------+----------------+
| myMemberID | int(10) unsigned | NO   | PRI | NULL    | auto_increment |
| youEmail   | varchar(40)      | NO   |     | NULL    |                |
| youName    | varchar(20)      | NO   |     | NULL    |                |
| youPass    | varchar(20)      | NO   |     | NULL    |                |
| youBirth   | int(20)          | NO   |     | NULL    |                |
| youAge     | int(5)           | NO   |     | NULL    |                |
| regTime    | int(20)          | NO   |     | NULL    |                |
+------------+------------------+------+-----+---------+----------------+
7 rows in set (0.00 sec)
테이블 삭제
drop table 테이블이름;
mysql> drop table member;
Query OK, 0 rows affected (0.01 sec)
 
mysql> show tables;
Empty set (0.00 sec)
truncate table 테이블이름; //테이블 내용 초기화
mysql> truncate table member;

🏙테이블 데이터

데이터 입력하기

INSERT INTO 테이블명(필드명) VALUES
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("webstoryboy@naver.com","황상연","1234","19990304","26","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("dlscks0930@naver.com","황인찬","1234","19980930","26","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("gp2617@naver.com","천설희","1234","19950313","29","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("dsy1943@naver.com","여다슬","1943","20011227","23","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("1346zany@gmail.com","이승연","1234","19991216","25","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("ebmdols@naver.com","장진용","1234","19940401","26","03140316");
INSERT INTO members(youEmail, youName, youpass, youBirth, youAge, regTime) VALUES("jo0132@naver.com","노지영","1234","19950323","29","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("skadldldl123@gmail.com","안교남","1234","19920923","32","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("ehcjswo1@gmail.com","김도현","123","19951003","29","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("goed0522@gmail.com","변우현","1234","20000629","24","03141516");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("yuna243441@naver.com","이유나","1234","20020508","22","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("im.kebab00@gmail.com","이요셉","1234","19990315","26","03140316");
INSERT INTO members(youEmail, youName, youpass, youBirth, youAge, regTime) VALUES("ture403@gmail.com","전윤기","1234","19920210","32","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("dongjin6539@naver.com","신동진","1234","19960709","28","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("gnsrbdi@naver.com","이훈규","1234","19950227","29","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("jeongyouna_@naver.com","정유나","1234","19950606","29","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("daanbi1345@gmail.com","조은경","1234","19930205","31","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("hunmi961119@gmail.com","진현미","1234","19961119","28","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("getgrovy@gmail.com","정희석","1234","19990101","26","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("kshkmn0929@naver.com","김도현","0929","20020929","22","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("hyejeong3283@gmail.com","이혜정","1234","19940622","30","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("didrn94553@gmail.com","이양구","1234","19941212","30","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("ghkddn132@naver.com","정황우","1234","19970130","25","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("esansi@naver.com","김현빈","1234","19970524","27","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("lee3ll@naver.com","이은지","1234","19930311","31","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("dripidea77@gmail.com","김시연","1234","19930313","31","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("itshena01@gmail.com","조한미","1234","19930211","31","03140316");
INSERT INTO members(youEmail, youName, youPass, youBirth, youAge, regTime) VALUES("aimee00418@gmail.com","권현정","1234","19830211","39","03140316");
INSERT INTO 테이블명(필드명) VALUES
INSERT INTO reviews(memberID, youText, regTime) VALUES("4", "정말 감사합니다. 잘봤어요", "1234567");
INSERT INTO reviews(memberID, youText, regTime) VALUES("14", "짱이에요!", "151124");
INSERT INTO reviews(memberID, youText, regTime) VALUES("2", "이건 정말 사야해요.", "655434");
INSERT INTO reviews(memberID, youText, regTime) VALUES("5", "내용이 좋아요~", "7465453");
INSERT INTO reviews(memberID, youText, regTime) VALUES("7", "잘 봤습니다~", "4123342");
INSERT INTO reviews(memberID, youText, regTime) VALUES("1", "정리 잘 하셨네요~!", "5342342");
INSERT INTO reviews(memberID, youText, regTime) VALUES("9", "사진 선택이 탁월합니다!", "3567542");
INSERT INTO reviews(memberID, youText, regTime) VALUES("4", "잘봤습니다~", "532342");
INSERT INTO reviews(memberID, youText, regTime) VALUES("2", "너무 좋은 내용이에요!", "324897");
INSERT INTO reviews(memberID, youText, regTime) VALUES("7", "좀 아쉽네요~", "1439127");

데이터 불러오기

SELECT 필드명 FROM 테이블명 WHERE 조건

전체 데이터 불러오기

mysql> SELECT * FROM member;
+------------+------------------------+---------+---------+----------+--------+---------+
| myMemberID | youEmail               | youName | youPass | youBirth | youAge | regTime |
+------------+------------------------+---------+---------+----------+--------+---------+
|          1 | webstoryboy@naver.com  | 황상연  | 1234    | 19990304 |     26 | 3140316 |
|          2 | dlscks0930@naver.com   | 황인찬  | 1234    | 19980930 |     26 | 3140316 |
|          3 | gp2617@naver.com       | 천설희  | 1234    | 19950313 |     29 | 3140316 |
|          4 | dsy1943@naver.com      | 여다슬  | 1943    | 20011227 |     23 | 3140316 |
|          5 | 1346zany@gmail.com     | 이승연  | 1234    | 19991216 |     25 | 3140316 |
|          6 | ebmdols@naver.com      | 장진용  | 1234    | 19940401 |     26 | 3140316 |
|          7 | jo0132@naver.com       | 노지영  | 1234    | 19950323 |     29 | 3140316 |
|          8 | skadldldl123@gmail.com | 안교남  | 1234    | 19920923 |     32 | 3140316 |
|          9 | ehcjswo1@gmail.com     | 김도현  | 123     | 19951003 |     29 | 3140316 |
|         10 | goed0522@gmail.com     | 변우현  | 1234    | 20000629 |     24 | 3141516 |
|         11 | yuna243441@naver.com   | 이유나  | 1234    | 20020508 |     22 | 3140316 |
|         12 | im.kebab00@gmail.com   | 이요셉  | 1234    | 19990315 |     26 | 3140316 |
|         13 | ture403@gmail.com      | 전윤기  | 1234    | 19920210 |     32 | 3140316 |
|         14 | dongjin6539@naver.com  | 신동진  | 1234    | 19960709 |     28 | 3140316 |
|         15 | gnsrbdi@naver.com      | 이훈규  | 1234    | 19950227 |     29 | 3140316 |
|         16 | jeongyouna_@naver.com  | 정유나  | 1234    | 19950606 |     29 | 3140316 |
|         17 | daanbi1345@gmail.com   | 조은경  | 1234    | 19930205 |     31 | 3140316 |
|         18 | hunmi961119@gmail.com  | 진현미  | 1234    | 19961119 |     28 | 3140316 |
|         19 | getgrovy@gmail.com     | 정희석  | 1234    | 19990101 |     26 | 3140316 |
|         20 | kshkmn0929@naver.com   | 김도현  | 0929    | 20020929 |     22 | 3140316 |
|         21 | hyejeong3283@gmail.com | 이혜정  | 1234    | 19940622 |     30 | 3140316 |
|         22 | didrn94553@gmail.com   | 이양구  | 1234    | 19941212 |     30 | 3140316 |
|         23 | ghkddn132@naver.com    | 정황우  | 1234    | 19970130 |     25 | 3140316 |
|         24 | esansi@naver.com       | 김현빈  | 1234    | 19970524 |     27 | 3140316 |
|         25 | lee3ll@naver.com       | 이은지  | 1234    | 19930311 |     31 | 3140316 |
|         26 | dripidea77@gmail.com   | 김시연  | 1234    | 19930313 |     31 | 3140316 |
|         27 | itshena01@gmail.com    | 조한미  | 1234    | 19930211 |     31 | 3140316 |
+------------+------------------------+---------+---------+----------+--------+---------+

memberID가 1번인 경우만 불러오기

mysql> SELECT * FROM member WHERE memberID = 1;

memberID가 1번이 아닌 경우 불러오기

mysql> SELECT * FROM member WHERE memberID <> 1;

memberID가 5~10번만 불러오기

mysql> SELECT * FROM member WHERE memberID >=5 AND memberID <= 10;

youAge가 30~40살만 불러오기

SELECT * FROM member WHERE youAge >=30 AND youAge <= 40;

youAge가 30~40살만 불러오기

SELECT * FROM member WHERE youAge BETWEEN 30 AND 40;

youAge가 30~40살 빼고 불러오기

SELECT * FROM member WHERE youAge NOT BETWEEN 30 AND 40;

memberID가 1, 5, 10, 15

SELECT * FROM member WHERE memberID IN(1,5,10,15);

youName 중에 데이터가 없는 것 불러오기

SELECT * FROM members WHERE youName IS NULL;

youName 중에 "연" 텍스트가 포함된 이름불러오기

SELECT * FROM member WHERE youName LIKE '%연%';

youName 중에 "김"으로 시작하는 이름불러오기

SELECT * FROM member WHERE youName LIKE '김%';

youName 중에 "현"으로 끝나는 이름불러오기

SELECT * FROM member WHERE youName LIKE '%현';

youName 중에 "상"이 들어가는 이름불러오기

SELECT * FROM member WHERE youName LIKE '_상_;

youName 중에 "김" 또는 "이"로 시작하는 이름불러오기

SELECT * FROM member WHERE youName LIKE '김%' OR youName LIKE '이%';

이름만 불러오기(내림차순)

SELECT youName FROM member ORDER by youName DESC;

이름만 불러오기(올림차순)

SELECT youName FROM member ORDER by youName ASC;

youName 갯수 구해오기

SELECT count(youName) FROM member;

member의 전체 갯수 구해오기

SELECT count(*) FROM member;

나이가 25세 이상이면서 아이디가 2또는 9인 사람

SELECT * FROM (memberID = 2 OR memberID = 9) AND youAge >= 25;

회원 데이터를 5개만 1~10 불러오기

SELECT * FROM member LIMIT 5;

회원 데이터를 5개만 6~10 불러오기

SELECT * FROM member LIMIT 5, 5;

회원 나이를 중복없이 불러오기

SELECT DISTINCT youAge FROM member;

나이가 25세 이상이면서 김씨 성을 갖고 있는사람의 이름불러오기

SELECT youName FROM member WHERE youAge >=25 AND youName LIKE '김%'

나이가 25세 이상이고 김씨 성을 갖고 있는사람의 이름불러오기

SELECT youName FROM member WHERE youAge >=25 OR youName LIKE '김%';

youName 필드만 불러오기

SELECT youName FROM member;

youName,youAge 필드만 불러오기

SELECT youName,youAge FROM member;

youName,youAge 필드만 나이30살이상 불러오기

SELECT youName,youAge FROM member WHERE youAge >=30;

데이터 수정

UPDATE 테이블명 SET 컬럼명 조건

모든 회원의 비밀번호를 1234로 수정하기

UPDATE member SET youPass = "1234";

아이디가 3번인 회원만 비밀번호 9999로 수정하기

UPDATE member SET youPass = "9999" WHERE memberID = '3';

아이디가 5~10번인 회원의 비밀번호를 7777로 수정하기

UPDATE member SET youPass = "7777" WHERE memberID BETWEEN 5 AND 10;

데이터 삭제

DELETE FROM 테이블명 WHERE 조건

아이디가 5번인 멤버 삭제

DELETE FROM member WHERE memberID = '5';

비밀번호가 1234인 사람들만 삭제

DELETE FROM member WHERE youPass = '1234';

멤버아이디 기준으로 5번째 멤버까지 삭제

DELETE FROM member ORDER BY memberID LIMIT 5;

멤버아이디 기준으로 7,9번 멤버 삭제

DELETE FROM member ORDER BY memberID IN(7,9);

🏙테이블 수정

필드 추가하기

ALTER TABLE [테이블명] ADD [추가할 필드명] AFTER [필드 위치]

멤버 테이블에 핸드폰 번호 필드를 추가

ALTER TABLE members ADD youPhone varchar(20) NOT NULL;

필드 수정하기

ALTER TABLE [테이블명] MODIFY [수정할 필드명]
ALTER TABLE members MODIFY youPhone int(20) NOT NULL;

필드 삭제하기

ALTER TABLE [테이블명] DROP [삭제할 필드명]
ALTER TABLE members DROP youPhone;

🏙테이블 합치기(JOIN)

SELECT [필드명] FROM [테이블명 엘리어스] JOIN [연결할 테이블명 엘리어스] ON [기준이 되는 조건문]

두개의 테이블 (members, review) 합치기

SELECT m.youEmail, m.youName, r.youText, r.regTime FROM members m JOIN reviews r ON (m.memberID = r.memberID);

두개의 테이블 (members, review) 합치기 : 필드명 변경하기(AS)

SELECT m.youEmail, m.youName, r.youText, r.regTime AS reviewRegTime FROM members m JOIN reviews r ON (m.memberID = r.memberID);

두개의 테이블 (members, review) 합치기 : 왼쪽 테이블 기준

SELECT m.youEmail, m.youName, r.youText, r.regTime FROM members m LEFT JOIN reviews r ON (m.memberID = r.memberID);

🏙집계 함수

두개의 테이블 (members, review) 합치기


                        CREATE TABLE schoolrecode (
                            studentID int(10) unsigned NOT NULL AUTO_INCREMENT comment '학생번호',
                            class tinytext comment "소속클래스(반)",
                            english tinytext NOT NULL comment "영어점수",
                            math tinytext NOT NULL comment "수학점수",
                            science tinytext NOT NULL comment "과학점수",
                            coding tinytext NOT NULL comment "코딩점수",
                            PRIMARY KEY(studentID)
                        ) charset=utf8 comment = "성적 정보";

                        INSERT INTO schoolrecode(english, math, science, coding) VALUES(50, 10, 20, 100);
                        INSERT INTO schoolrecode(class, english, math, science, coding) VALUES(1, 50, 10, 20, 100);
                        INSERT INTO schoolrecode(class, english, math, science, coding) VALUES(2, 40, 30, 22, 90);
                        INSERT INTO schoolrecode(class, english, math, science, coding) VALUES(2, 50, 40, 23, 80);
                        INSERT INTO schoolrecode(class, english, math, science, coding) VALUES(3, 60, 50, 24, 70);
                        INSERT INTO schoolrecode(class, english, math, science, coding) VALUES(4, 70, 60, 25, 60);
                        INSERT INTO schoolrecode(class, english, math, science, coding) VALUES(5, 80, 70, 26, 50);

레코드 갯수 구하기

SELECT count(class) FROM schoolrecode;
SELECT count(*) FROM schoolrecode;

코딩 합계 구하기

SELECT sum(coding) FROM schoolrecode;

코딩 합계 구하기 (학생 아이디가 1~4)

SELECT sum(coding) FROM schoolrecode where studentID >=1 AND studentID <=4;

가장 높은 코딩 점수 구하기

SELECT max(coding) FROM schoolrecode;

코딩 평균 점수 구하기

SELECT avg(coding) FROM schoolrecode;

그룹별 집계

SELECT [필드명] FROM [테이블명] GROUP BY [필드명]

반별로 학생들의 영어 점수 평균값 구하기

SELECT class, avg(english) FROM schoolrecode WHERE class IN(1,2,3,4,5) GROUP BY class;

반별로 학생들의 수학 점수 합계 구하기

SELECT class, sum(math) FROM schoolrecode WHERE class IN(1,2,3,4,5) GROUP BY class;

반별로 학생들의 수학 점수 합계 점수가 70점 이상

SELECT class, sum(math) FROM schoolrecode WHERE class IN(1,2,3,4,5) GROUP BY class HAVING sum(math) >= 70;

출력 결과의 정령

SELECT [필드명] FROM [테이블명] GROUP BY [필드명] DESC 또는 ASC

영어 점수를 높은 순에서 낮은 순으로 표시

SELECT studentID, english FROM schoolrecode ORDER by english DESC;

영어 점수를 낮은 순에서 높은 순으로 표시

SELECT studentID, english FROM schoolrecode ORDER by english ASC;

반별 수학 점수를 높은 순에서 낮은 순으로 표시

SELECT class, sum(math) FROM schoolrecode WHERE class IN(1,2,3,4,5) GROUP BY class ORDER by sum(math) DESC;