기존의 필드삭제하기(alter table)

[root@RockyLinux wpDB]# mysql -u root -p TESTDB

Enter password:

Reading table information for completion of table and column names

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Your MariaDB connection id is 43

Server version: 10.5.16-MariaDB MariaDB Server

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MariaDB [TESTDB]>

MariaDB [TESTDB]> desc testtable;

+---------+-----------------------+------+-----+---------+-------+

| Field   | Type                  | Null | Key | Default | Extra |

+---------+-----------------------+------+-----+---------+-------+

| uid     | mediumint(4) unsigned | NO   | PRI | 0       |       |

| name    | varchar(12)           | NO   |     |         |       |

| email   | varchar(20)           | NO   |     |         |       |

| website | varchar(50)           | YES  |     | NULL    |       |

+---------+-----------------------+------+-----+---------+-------+

4 rows in set (0.001 sec)

MariaDB [TESTDB]>

MariaDB [TESTDB]> alter table testtable drop column website;

Query OK, 0 rows affected (0.010 sec)

Records: 0  Duplicates: 0  Warnings: 0

MariaDB [TESTDB]>

MariaDB [TESTDB]> desc testtable;

+-------+-----------------------+------+-----+---------+-------+

| Field | Type                  | Null | Key | Default | Extra |

+-------+-----------------------+------+-----+---------+-------+

| uid   | mediumint(4) unsigned | NO   | PRI | 0       |       |

| name  | varchar(12)           | NO   |     |         |       |

| email | varchar(20)           | NO   |     |         |       |

+-------+-----------------------+------+-----+---------+-------+

3 rows in set (0.001 sec)

MariaDB [TESTDB]>