MySQL虚拟GENERATED COLUMNS如何与数学表达式一起使用？
可以借助一个示例进行说明，在该示例中，我们在名为“triangle”的表中创建虚拟生成的列。众所周知，可以在使用或不使用关键字'virtual'的情况下生成虚拟生成的列。
示例
mysql> Create table triangle(SideA DOUBLE, SideB DOUBLE, SideC DOUBLE AS (SQRT(SideA * SideB + SideB * SideB))); mysql> Describe Triangle; +-------+--------+------+-----+---------+-------------------+ | Field | Type | Null | Key | Default | Extra | +-------+--------+------+-----+---------+-------------------+ | SideA | double | YES | | NULL | | | SideB | double | YES | | NULL | | | SideC | double | YES | | NULL | VIRTUAL GENERATED | +-------+--------+------+-----+---------+-------------------+ 3 rows in set (0.00 sec)
上面的描述表明，列SideC是虚拟生成的列。
mysql> INSERT INTO triangle(SideA, SideB) Values(1,1),(3,4),(6,8); Records: 3 Duplicates: 0 Warnings: 0 mysql> Select * from triangle; +-------+-------+--------------------+ | SideA | SideB | SideC | +-------+-------+--------------------+ | 1 | 1 | 1.4142135623730951 | | 3 | 4 | 5.291502622129181 | | 6 | 8 | 10.583005244258363 | +-------+-------+--------------------+ 3 rows in set (0.03 sec)