Passing parameters to functions

User-defined functions are not invoked with the CALL statement, but are used in the same manner that built-in functions are. For example, the following statement uses the FullName function defined in Creating user-defined functions to retrieve the names of employees:

To list the names of all employees

  • In Interactive SQL, type the following:

    SELECT FullName( GivenName, Surname ) AS Name
       FROM Employees;
Name
Fran Whitney
Matthew Cobb
Philip Chin
Julie Jordan
...
Notes
  • Default parameters can be used in calling functions. However, parameters cannot be passed to functions by name.
  • Parameters are passed by value, not by reference. Even if the function changes the value of the parameter, this change is not returned to the calling environment.
  • Output parameters cannot be used in user-defined functions.
  • User-defined functions cannot return result sets.