Sybase 12.4.2 manual Declarations in compound statements, 241

CHAPTER 6 Using Procedures and Batches

A command delimiter is required after every statement in a statement list except for the last, where it is optional.

Declarations in compound statements

Local declarations in a compound statement immediately follow the BEGIN keyword. These local declarations exist only within the compound statement. The following may be declared within a compound statement:

•Variables

•Cursors

•Temporary tables

•Exceptions (error identifiers)

Local declarations can be referenced by any statement in that compound statement, or in any compound statement nested within it. Local declarations are not visible to other procedures called from the compound statement.

The following user-defined function illustrates local declarations of variables.

The customer table includes some Canadian customers sprinkled among those from the USA, but there is no country column. The user-defined function nationality uses the fact that the US zip code is numeric while the Canadian postal code begins with a letter to distinguish Canadian and US customers.

CREATE FUNCTION nationality( cust_id INT )

RETURNS CHAR( 20 )

BEGIN

DECLARE natl CHAR(20);

IF cust_id IN ( SELECT id FROM customer

WHERE LEFT(zip,1) > ’9’) THEN

SET natl = ’CDN’;

ELSE

SET natl = ’USA’;

END IF;

RETURN ( natl );

END

This example declares a variable natl to hold the nationality string, uses a SET statement to set a value for the variable, and returns the value of the natl string to the calling environment.

The following query lists all Canadian customers in the customer table:

SELECT *

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