✔ table생성
mysql> create database school;
Query OK, 1 row affected (0.01 sec)
mysql> use school;
Database changed
mysql> create table student(
-> std_num varchar(10),
-> std_name varchar(20) not null,
-> std_major varchar(20),
-> std_term int,
-> std_point int,
-> primary key(std_num));
Query OK, 0 rows affected (0.01 sec)
mysql> desc student;
+-----------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-----------+-------------+------+-----+---------+-------+
| std_num | varchar(10) | NO | PRI | NULL | |
| std_name | varchar(20) | NO | | NULL | |
| std_major | varchar(20) | YES | | NULL | |
| std_term | int | YES | | NULL | |
| std_point | int | YES | | NULL | |
+-----------+-------------+------+-----+---------+-------+
5 rows in set (0.01 sec)
mysql> create table course(
-> co_code varchar(12),
-> co_name varchar(20) not null,
-> co_professor varchar(20),
-> co_point int,
-> co_time int,
-> co_timetable varchar(40),
-> primary key(co_code));
Query OK, 0 rows affected (0.01 sec)
mysql> desc course;
+--------------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+--------------+-------------+------+-----+---------+-------+
| co_code | varchar(12) | NO | PRI | NULL | |
| co_name | varchar(20) | NO | | NULL | |
| co_professor | varchar(20) | YES | | NULL | |
| co_point | int | YES | | NULL | |
| co_time | int | YES | | NULL | |
| co_timetable | varchar(40) | YES | | NULL | |
+--------------+-------------+------+-----+---------+-------+
6 rows in set (0.00 sec)
mysql> create table attend(
-> at_num int auto_increment,
-> at_std_num varchar(10),
-> at_co_code varchar(12),
-> at_year int,
-> at_term int,
-> at_mid int default 0,
-> at_final int default 0,
-> at_attend int default 0,
-> at_hw int default 0,
-> at_repetition varchar(1) default 'n',
-> at_score varchar(4),
-> primary key(at_num)
-> );
Query OK, 0 rows affected (0.01 sec)
mysql> desc attend;
+---------------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+---------------+-------------+------+-----+---------+----------------+
| at_num | int | NO | PRI | NULL | auto_increment |
| at_std_num | varchar(10) | YES | | NULL | |
| at_co_code | varchar(12) | YES | | NULL | |
| at_year | int | YES | | NULL | |
| at_term | int | YES | | NULL | |
| at_mid | int | YES | | 0 | |
| at_final | int | YES | | 0 | |
| at_attend | int | YES | | 0 | |
| at_hw | int | YES | | 0 | |
| at_repetition | varchar(1) | YES | | n | |
| at_score | varchar(4) | YES | | NULL | |
+---------------+-------------+------+-----+---------+----------------+
11 rows in set (0.00 sec)
mysql> alter table attend add foreign key(at_std_num) references student(std_num);
Query OK, 0 rows affected (0.03 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> alter table attend add foreign key(at_co_code) references course(co_code);
Query OK, 0 rows affected (0.03 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> desc attend;
+---------------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+---------------+-------------+------+-----+---------+----------------+
| at_num | int | NO | PRI | NULL | auto_increment |
| at_std_num | varchar(10) | YES | MUL | NULL | |
| at_co_code | varchar(12) | YES | MUL | NULL | |
| at_year | int | YES | | NULL | |
| at_term | int | YES | | NULL | |
| at_mid | int | YES | | 0 | |
| at_final | int | YES | | 0 | |
| at_attend | int | YES | | 0 | |
| at_hw | int | YES | | 0 | |
| at_repetition | varchar(1) | YES | | n | |
| at_score | varchar(4) | YES | | NULL | |
+---------------+-------------+------+-----+---------+----------------+
11 rows in set (0.00 sec)