更多數學函式
SQL Server 中級
Ginger Grant
Instructor
絕對值
使用 ABS() 回傳非負值
ABS(number)
在 T-SQL 使用 ABS（I）
SELECT ABS(-2.77), ABS(3), ABS(-2)
+--------------------+-------------------+-------------------+
|(No column name) |(No column name) |(No column name) |
+--------------------+-------------------+-------------------+
|2.77 |3 |2 |
+--------------------+-------------------+-------------------+
在 T-SQL 使用 ABS（II）
SELECT DurationSeconds, ABS(DurationSeconds) AS AbsSeconds
FROM Incidents
+--------------------+--------------------+
|DurationSeconds |AbsSeconds |
+--------------------+--------------------+
|-25.36 |25.36 |
|-258482.44 |258482.44 |
|45.66 |45.66 |
+--------------------+--------------------+
平方與平方根（T-SQL）
SELECT SQRT(9) AS Sqrt,
SQUARE(9) AS Square
+--------+-----------+
|Sqrt |Square |
+--------------------+
|3 |81 |
+--------+-----------+
對數
LOG()回傳自然對數- 你也可指定底數，未指定時為 2.718281828
LOG(number [,Base])
在 T-SQL 計算對數
SELECT DurationSeconds, LOG(DurationSeconds, 10) AS LogSeconds
FROM Incidents
+--------------------+--------------------+
|DurationSeconds |LogSeconds |
+--------------------+--------------------+
|37800 |4.577491799837225 |
|5 |0.6989700043360187 |
|20 |1.301029995663981 |
...
+--------------------+--------------------+
0 的對數
你不能對 0 取對數，否則會發生錯誤。
SELECT LOG(0, 10)
An invalid floating point operation occurred.
一起來練習吧！
SQL Server 中級
