可以通过一个示例来说明,在该示例中,我们在名为“triangle_stored”的表中创建一个存储的生成列。我们知道,存储生成列可以通过使用关键字“stored”来生成。
示例
mysql> Create table triangle_stored(SideA DOUBLE, SideB DOUBLE, SideC DOUBLE AS (SQRT(SideA * SideB + SideB * SideB)) STORED); Query OK, 0 rows affected (0.47 sec) mysql> Describe triangle_stored; +-------+--------+------+-----+---------+------------------+ | Field | Type | Null | Key | Default | Extra | +-------+--------+------+-----+---------+------------------+ | SideA | double | YES | | NULL | | | SideB | double | YES | | NULL | | | SideC | double | YES | | NULL | STORED GENERATED | +-------+--------+------+-----+---------+------------------+ 3 rows in set (0.00 sec) mysql> INSERT INTO triangle_stored(SideA, SideB) Values(1,1),(3,4),(6,8); Query OK, 3 rows affected (0.09 sec) Records: 3 Duplicates: 0 Warnings: 0 mysql> Select * from triangle_stored; +-------+-------+--------------------+ | SideA | SideB | SideC | +-------+-------+--------------------+ | 1 | 1 | 1.4142135623730951 | | 3 | 4 | 5.291502622129181 | | 6 | 8 | 10.583005244258363 | +-------+-------+--------------------+ 3 rows in set (0.00 sec)原文来自:www.php.cn
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