Numeric Functions
PL/SQL implements a number of functions that are useful when working with numbers. We list those functions in Table 9-6, and describe each of them in detail in the sections that follow.
| Table 9-6. PL/SQL's built-in numeric functions | |
| Name | Description |
| ABS | Returns the absolute value of a number. |
| ACOS | Returns the inverse cosine. |
| ASIN | Returns the inverse sine. |
| ATAN | Returns the inverse tangent. |
| ATAN2 | Returns the inverse tangent of a value, but allows you to pass that value differently than when using ATAN. |
| BITAND | Performs an AND operation on the bits from two positive integer numbers. |
| CEIL | Returns the smallest integer greater than or equal to the specified number. |
| COS | Returns the cosine. |
| COSH | Returns the hyperbolic cosine. |
| EXP (n) | Returns the number e raised to the nth power, where e = 2.71828183... |
| FLOOR | Returns the largest integer equal to or less than the specified number. |
| LN (a) | Returns the natural logarithm of a. |
| LOG (a, b) | Returns the logarithm, base a, of b. |
| MOD (a, b) | Returns the remainder of a divided by b. |
| POWER (a, b) | Returns a raised to the bth power. |
| ROUND (a, [b]) | Returns a rounded to b decimal places. |
| SIGN (a) | Returns 1 if a is positive, 0 if a is 0, and -1 if a is less than 0 (i.e., negative). |
| SIN | Returns the sine. |
| SINH | Returns the hyperbolic sine. |
| SQRT | Returns the square root of a number. |
| TAN | Returns the tangent. |
| TANH | Returns the hyperbolic tangent. |
| TRUNC (a, [b]) | Returns a truncated to b decimal places. |
Note that the trigonometric and logarithmic functions are available only in PL/SQL Version 2.0 and subsequent releases. The inverse trigonometric functions are available only in PL/SQL Release 2.3 and higher.
When using the trigonometric functions, be aware that all angles are expressed in radians, not in degrees. You can convert between radians and degrees as follows:
radians = 
* degrees / 180 -- From degrees to radians
degrees = radians * 180 / -- From radians to degrees
Oracle Corporation did not implement a function for (pi) itself. However, you can obtain the value for through the following call:
The inverse cosine (ACOS) of -1 happens to be defined as exactly . Of course, because is a never-ending decimal number, you always have to work with an approximation. Use the ROUND function if you wish to round the results of ACOS(-1) to a specific number of decimal places.
We'll look quickly at the rounding and truncation functions, and then provide summaries of each of PL/SQL's built-in numeric functions. For each, we'll include the specification, some examples, and a brief description.