SQL ALTER TABLE簡單使用
本次環境使用的是MySQL5.7版 1. 新增一個欄位至該表 ALTER TABLE tableName ADD column_name datatype; mysql> SELECT * FROM Persons_copy; +----------+----------+-----------+---------+------+ | PersonID | LastName | FirstName | Address | City | +----------+----------+-----------+---------+------+ | 11 | Lester | Mark | No | No | +----------+----------+-----------+---------+------+ 1 row in set (0.00 sec) mysql> ALTER TABLE Persons_copy ADD column_name varchar(255); Query OK, 0 rows affected (0.42 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> SELECT * FROM Persons_copy; +----------+----------+-----------+---------+------+-------------+ | PersonID | LastName | FirstName | Address | City | column_name | +----------+----------+-----------+---------+------+-------------+ | 11 | Lester | Mark | No | No | NULL | +----------+----------+-----------+---------+------+-------------+ 1 row in set (0.00 sec) 2. 刪除一個欄位至該表 ALTER TABLE tableName DROP column...