21.3.7 / SQL / SQL 실습, SQLD 문제풀이

Today

강의

MySQL 데이터베이스 한번에 끝내기 SQL Full Tutorial Course using MySQL Database (5회차 완료)

스터디 내용

  • SQL 실습 강좌 복습
  • SQLD 노란책 2과목 107번까지 풀이

결과

alter table test2 add col4 int null;

alter table test2 modify col4 varchar(40) not null;

alter table test2 drop col4;

create unique index col1idx
on test (col1);

show index from test;

alter table test add fulltext col3idx(col3);

show index from test;

alter table test drop index col3idx;

drop index col2idx on test;

create view testview as
select col1, col2
from test;

select * from testview;

alter view testview as select col1,col2,col3
from test;

drop view testview;

use world;

create view adda as
select city.Name, country.surfacearea, 
city.populaton from city
join country on city.countrycode = country.code
join countrylanguage 
on 
city.countrycode = countrylanguage.countrycode;

insert into test value(1,123,1.1,'test');

insert into test2 select * from test;

update test set col1 = 1, col2 = 1.0, col3 = 'test'
where id = 1;

delete from test where id = 1;

truncate table test;

drop table test;

select * from city where countrycode = (
select countrycode from city where name = 
'seoul');

select * from city where population > any (
select population from city where District = 
'New York');

select * from city where population > all (
select population from city where District = 
'New York');

select locate('abc', '1123123abc');

select left
('mysql is an open source relational ddd',5);

select right
('mysql is an open source relational ddd',5);

select lower('mysql is an open source relational');
select upper('mysql is an open source relational');

select replace('mysql','my','ms');

select trim('        sdf  ');
select trim(leading '#' from '###qewf###'),
trim(trailing '#' from '###qewf###'),
trim(both '#' from '###qewf###');

select format(1231231231231,3);

select floor(10.9), ceil(10.9), round(10.9);

select date_format(now(), '%Y-%m-%d');

Tomorrow

  • SQLD 2과목 120번
  • 인프런 sql 강의 복습

Summary

  • 반복 반복!

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