Algorithms/DDL.txt at master · vikaspatra/Algorithms · GitHub

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DDL COMMANDS:-

CREATING TABLE:-

mysql> create table employee
    -> (
    -> emp_no int primary key,
    -> emp_name varchar(20),
    -> branch varchar(10)
    -> );
Query OK, 0 rows affected (0.09 sec)

mysql> desc employee;
+----------+-------------+------+-----+---------+-------+
| Field    | Type        | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+-------+
| emp_no   | int(11)     | NO   | PRI | NULL    |       |
| emp_name | varchar(20) | YES  |     | NULL    |       |
| branch   | varchar(10) | YES  |     | NULL    |       |
+----------+-------------+------+-----+---------+-------+
3 rows in set (0.00 sec)

ALTERING TABLE:-

mysql> alter table employee add salary int;
Query OK, 0 rows affected (0.08 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> desc employee;
+----------+-------------+------+-----+---------+-------+
| Field    | Type        | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+-------+
| emp_no   | int(11)     | NO   | PRI | NULL    |       |
| emp_name | varchar(20) | YES  |     | NULL    |       |
| branch   | varchar(10) | YES  |     | NULL    |       |
| salary   | int(11)     | YES  |     | NULL    |       |
+----------+-------------+------+-----+---------+-------+
4 rows in set (0.00 sec)

DISPLAYING TABLE:-

mysql> alter table employee drop salary;
Query OK, 0 rows affected (0.05 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> desc employee;
+----------+-------------+------+-----+---------+-------+
| Field    | Type        | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+-------+
| emp_no   | int(11)     | NO   | PRI | NULL    |       |
| emp_name | varchar(20) | YES  |     | NULL    |       |
| branch   | varchar(10) | YES  |     | NULL    |       |
+----------+-------------+------+-----+---------+-------+
3 rows in set (0.00 sec)

mysql> drop employee;
Query OK, 0 rows affected (0.05 sec)