💡오늘 한 것

MYSQL

• show databases;

• use [DATABASE 이름];

• show tables;

• create table ex)
  create table tableName(
  id int(10) unsigned auto_increment not null primary key comment"table`s id",
  title varchar(512) not null comment "title",
  contents text not null comment "contents",
  count int(11) default 0 comment "count",
  created_at datetime default current_timestamp() comment "time");

• insert into [table name]([column name1], [colunm name2], ...) values("[column name1's values]", "[column name2's values]", ...);

• show create table [table name];

• insert into [A테이블명] (title, contents, count, created_at) select title, contents, count, created_at from [A테이블명에 포함 될 테이블명]

• ALTER TABLE [table] ADD INDEX [인덱스명]([인덱스 설정 컬럼01], [인덱스 설정 컬럼02])

• select * from [table] order by [column] desc;

• select count(*) from [table]

• select count(column) from [table]