如何使用 CREATE TABLE 语句在 MySQL 表中拥有多个存储生成列?
mysqlmysqli database
在 MySQL 表中添加多个存储生成列是完全可能的。可以用以下示例来说明 −
示例
mysql> Create table profit1(cost int, price int, profit int AS (price-cost) STORED, price_revised int AS (price-2) STORED); Query OK, 0 rows affected (0.36 sec) mysql> Describe profit1; +---------------+---------+------+-----+---------+------------------+ | Field | Type | Null | Key | Default | Extra | +---------------+---------+------+-----+---------+------------------+ | cost | int(11) | YES | | NULL | | | price | int(11) | YES | | NULL | | | profit | int(11) | YES | | NULL | STORED GENERATED | | price_revised | int(11) | YES | | NULL | STORED GENERATED | +---------------+---------+------+-----+---------+------------------+ 4 rows in set (0.00 sec) mysql> Insert into profit1(Cost, Price) values(100,110); Query OK, 1 row affected (0.09 sec) mysql> Insert into profit1(Cost, Price) values(200,220); Query OK, 1 row affected (0.09 sec) mysql> Select * from profit1; +------+-------+--------+---------------+ | cost | price | profit | price_revised | +------+-------+--------+---------------+ | 100 | 110 | 10 | 108 | | 200 | 220 | 20 | 218 | +------+-------+--------+---------------+ 2 rows in set (0.00 sec)
