July 2023
Intermediate to advanced
278 pages
5h 40m
Chinese
Content preview from Trino 权威指南：原书第2版
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172
|
第
9
章
表 9-5：三角函数
函数 描述
cos(
x
)
x
的余弦
acos(
x
)
x
的反余弦
cosh(
x
)
x
的双曲余弦
sin(
x
)
x
的正弦
asin(
x
)
x
的反正弦
tan(
x
)
x
的正切
atan(
x
)
x
的反正切
atan2(
y
,
x
)
y
/
x
的反正切
tanh(
x
)
x
的双曲正切
9.9
常数和随机函数
Trino
提供了一组函数，它们返回数学常数、概念值或随机值，如表
9-6
所示。
表 9-6：数学常数和函数
函数 返回类型 描述 示例
e() DOUBLE 欧拉数 2.718281828459045
pi() DOUBLE 圆周率 3.141592653589793
infinity() DOUBLE 用于表示无穷大的 Trino 常量 Infinity
nan() DOUBLE 用于表示不是一个数字的 Trino 常量 NaN
random() DOUBLE 大于等于 0.0 且小于 1.0 的 DOUBLE 数值 SELECT random()
random(
n
) 同输入 大于等于 0.0 并小于
n
的 DOUBLE 数值 SELECT random(100)
9.10
字符串函数和运算符
字符串操作是另一种常见的用例，对此
Trino
提供了丰富的支持。
||
运算符用于将字符
串拼接起来：
SELECT 'Emily' || ' Grace';
_col0
-------------
Emily Grace
(1 row)
Trino
提供了几个有用的字符串函数，如表
9-7
所示。
Trino权威指南 ...
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.