use market_db;
create table table1
(
col1 int primary key,
col2 int,
col3 int
);
show index from table1;
create table table2
(
col1 int primary key,
col2 int unique,
col3 int unique
);
show index from table2;
use market_db;
drop table if exists buy, member;
create table member
(
mem_id char(8),
mem_name varchar(10),
mem_number int,
addr char(2)
);
insert into member values('TWC', '트와이스',9,'서울');
insert into member values('BLK', '블랙핑크',4,'경남');
insert into member values('WMN', '여자친구',6,'경기');
insert into member values('OMY', '오마이걸',7,'서울');
select * from member;
alter table member
add constraint
primary key(mem_id);
select * from member;
alter table member drop primary key;
alter table member
add constraint
primary key(mem_name);
select * from member;
insert into member values('GRL', '소녀시대', 8, '서울');
select * from member;
drop table if exists member;
create table member
(
mem_id char(8),
mem_name varchar(10),
mem_number int,
addr char(2)
);
insert into member values('TWC', '트와이스',9,'서울');
insert into member values('BLK', '블랙핑크',4,'경남');
insert into member values('WMN', '여자친구',6,'경기');
insert into member values('OMY', '오마이걸',7,'서울');
select * from member;
alter table member
add constraint
unique (mem_id);
select * from member;
insert into member values('GRL', '소녀시대', 8, '서울');
select * from member;