Sybase 12.4.2 manual Calling user-defined functions, Introduction to user-defined functions, 236

CREATE FUNCTION

Introduction to user-defined functions

If you are using a tool other than DBISQL or Sybase Central, you may need to change the command delimiter away from the semicolon before entering the

statement.

CREATE FUNCTION fullname (firstname CHAR(30), lastname CHAR(30))

RETURNS CHAR(61)

BEGIN

DECLARE name CHAR(61);

SET name = firstname ’ ’ lastname; RETURN ( name );

END

For a complete description of the CREATE FUNCTION syntax, see Adaptive

Server IQ Reference Manual.

The CREATE FUNCTION syntax differs slightly from that of the CREATE

PROCEDURE statement. The following are distinctive differences:

•No IN, OUT, or INOUT keywords are required, as all parameters are IN parameters.

•The RETURNS clause is required to specify the data type being returned.

•The RETURN statement is required to specify the value being returned.

Calling user-defined functions

A user-defined function can be used, subject to permissions, in any place that a built-in non-aggregate function is used.

The following statement in DBISQL returns a full name from two columns containing a first and last name:

SELECT fullname (emp_fname, emp_lname)

FROM employee;

fullname (emp_fname, emp_lname)

Fran Whitney

Matthew Cobb

Philip Chin

...

The following statement in DBISQL returns a full name from a supplied first and last name:

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