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SQRT

描述

返回一个值的平方根,要求输入值大于或等于 0。

语法

SQRT(<x>)

参数

参数描述
<x>需要被计算平方根的值

返回值

参数 x 的平方根

特殊情况处理

  • x 等于 0 时,返回 0
  • x 等于 -0 时,返回 -0
  • x 小于 0 时,返回 NULL
  • x 为 NaN 时,返回 NaN
  • x 为正无穷大时,返回 Infinity
  • x 为负无穷大时,返回 NULL
  • x 为 NULL 时,返回 NULL

示例

select sqrt(9), sqrt(2);
+-------------------------+-------------------------+
| sqrt(cast(9 as DOUBLE)) | sqrt(cast(2 as DOUBLE)) |
+-------------------------+-------------------------+
| 3.0 | 1.4142135623730951 |
+-------------------------+-------------------------+
select sqrt(1.0);
+------------+
| sqrt(1.0) |
+------------+
| 1 |
+------------+
select sqrt(0.0);
+------------+
| sqrt(0.0) |
+------------+
| 0 |
+------------+
select sqrt(-0.0);
+-------------+
| sqrt(-0.0) |
+-------------+
| -0 |
+-------------+
select sqrt(-1.0);
+-------------+
| sqrt(-1.0) |
+-------------+
| NULL |
+-------------+
select sqrt(cast('nan' as double));
+---------------------------+
| sqrt(cast('nan' AS DOUBLE)) |
+---------------------------+
| NaN |
+---------------------------+
select sqrt(cast('inf' as double));
+---------------------------+
| sqrt(cast('inf' AS DOUBLE)) |
+---------------------------+
| Infinity |
+---------------------------+
select sqrt(cast('-inf' as double));
+----------------------------+
| sqrt(cast('-inf' AS DOUBLE)) |
+----------------------------+
| NULL |
+----------------------------+