MySQL 中 DEGREES(X) 函数用来返回参数 X,从弧度转换为度数。
DEGREES(X)X 待转换的弧度
(1)将弧度 PI() 转换成度数,如下:
mysql> SELECT PI(), DEGREES(PI());
+----------+---------------+
| PI() | DEGREES(PI()) |
+----------+---------------+
| 3.141593 | 180 |
+----------+---------------+
1 row in set (0.04 sec)
mysql> SELECT PI(), DEGREES(PI() / 2);
+----------+-------------------+
| PI() | DEGREES(PI() / 2) |
+----------+-------------------+
| 3.141593 | 90 |
+----------+-------------------+
1 row in set (0.03 sec)