ln

description

Syntax

DOUBLE ln(DOUBLE x) 返回以e为底的x的自然对数.

example

1. mysql> select ln(1);
2. +---------+
3. | ln(1.0) |
4. +---------+
5. |       0 |
6. +---------+
7. mysql> select ln(e());
8. +---------+
9. | ln(e()) |
10. +---------+
11. |       1 |
12. +---------+
13. mysql> select ln(10);
14. +--------------------+
15. | ln(10.0)           |
16. +--------------------+
17. | 2.3025850929940459 |
18. +--------------------+

keywords

1. LN