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Add and drop columns

      
mysql>
mysql> CREATE TABLE InStock
    -> (
    ->     ProductID SMALLINT
    -> );
Query OK, 0 rows affected (0.00 sec)

mysql>
mysql> ALTER TABLE InStock
    -> ADD COLUMN Quantity SMALLINT UNSIGNED NOT NULL,
    -> MODIFY ProductID SMALLINT UNSIGNED NOT NULL,
    -> ADD PRIMARY KEY (ProductID);
Query OK, 0 rows affected (0.01 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql>
mysql>
mysql> ALTER TABLE InStock
    -> DROP COLUMN Quantity,
    -> DROP PRIMARY KEY;
Query OK, 0 rows affected (0.01 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql>
mysql> DROP TABLE InStock;
Query OK, 0 rows affected (0.00 sec)

mysql>








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