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mysql>
mysql>
mysql> CREATE TABLE myTable(
-> ID SMALLINT
-> );
Query OK, 0 rows affected (0.27 sec)
mysql> desc myTable;
+-------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| ID | smallint(6) | YES | | NULL | |
+-------+-------------+------+-----+---------+-------+
1 row in set (0.00 sec)
mysql>
mysql> ALTER TABLE myTable
-> ADD COLUMN Quantity SMALLINT UNSIGNED NOT NULL,
-> MODIFY ID SMALLINT UNSIGNED NOT NULL,
-> ADD PRIMARY KEY (ID);
Query OK, 0 rows affected (0.08 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql>
mysql> desc myTable;
+----------+----------------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------+----------------------+------+-----+---------+-------+
| ID | smallint(5) unsigned | NO | PRI | | |
| Quantity | smallint(5) unsigned | NO | | | |
+----------+----------------------+------+-----+---------+-------+
2 rows in set (0.00 sec)
mysql>
mysql>
mysql> ALTER TABLE myTable
-> DROP COLUMN Quantity,
-> DROP PRIMARY KEY;
Query OK, 0 rows affected (0.05 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql>
mysql> desc myTable;
+-------+----------------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+----------------------+------+-----+---------+-------+
| ID | smallint(5) unsigned | NO | | | |
+-------+----------------------+------+-----+---------+-------+
1 row in set (0.01 sec)
mysql>
mysql>
mysql> drop table myTable;
Query OK, 0 rows affected (0.02 sec)
mysql>
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