MySQL 存储的生成列如何与数学表达式一起使用？

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 | 1.414两1356两3730951 |
|     3 |     4 | 5.两9150两6二两1二9181  |
|     6 |     8 | 10.583005两44两58363 |
+-------+-------+--------------------+
3 rows in set (0.00 sec)