Calling a Function : Function « Function Procedure Packages « Oracle PL/SQL Tutorial

You call your own functions as you would call any of the built-in database functions.

SQL>
SQL> CREATE OR REPLACE FUNCTION circle_area (p_radius IN NUMBER) RETURN NUMBER AS
  2    v_pi NUMBER := 3.14;
  3    v_area NUMBER;
  4  BEGIN
  5    v_area := v_pi * POWER(p_radius, 2);
  6    RETURN v_area;
  7  END circle_area;
  8  /

Function created.

SQL>
SQL> select circle_area(12) from dual;

CIRCLE_AREA(12)
---------------
         452.16

27.1.Function
	27.1.1.	Functions
	27.1.2.	Describe a user-defined function
	27.1.3.	create or replace FUNCTION iifn(boolean_expression in BOOLEAN,true_number IN NUMBER,false_number IN NUMBER)
	27.1.4.	Storing PL/SQL function in the Database
	27.1.5.	Create a simple function
	27.1.6.	Creating a Function to deal with business rules
	27.1.7.	CREATE OR REPLACE a function
	27.1.8.	Calling a Function
	27.1.9.	Calling a Function for a table
	27.1.10.	Function without parameters
	27.1.11.	Exit a function
	27.1.12.	How to Call a Function from PL/SQL With or Without Parameters
	27.1.13.	Local Subprograms
	27.1.14.	Dependency Example
	27.1.15.	The FullName Function
	27.1.16.	PLW-05005: function NO_RETURN returns without value at line 21
	27.1.17.	Use function to check passwords