很可能在 MySQL 表中添加多个存储的生成列。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)