rem 
rem $Header: examp1.sql,v 1.1 1992/05/12 22:02:06 RVASIRED Exp $ 
rem 
Rem  Copyright (c) 1991 by Oracle Corporation 
Rem    NAME
Rem      examp1.sql - <one-line expansion of the name>
Rem    DESCRIPTION
Rem      <short description of component this file declares/defines>
Rem    RETURNS
Rem 
Rem    NOTES
Rem      <other useful comments, qualifications, etc.>
Rem    MODIFIED   (MM/DD/YY)
Rem     rvasired   05/12/92 -  Creation 
/*
** This block processes an order for tennis rackets.  It decrements
** the quantity of rackets on hand only if there is at least one
** racket left in stock.
**
** Copyright (c) 1989,1992 by Oracle Corporation
*/

DECLARE
    qty_on_hand  NUMBER(5);
BEGIN
    SELECT quantity INTO qty_on_hand FROM inventory
        WHERE product = 'TENNIS RACKET'
        FOR UPDATE OF quantity;

    IF qty_on_hand > 0 THEN  -- check quantity
        UPDATE inventory SET quantity = quantity - 1
            WHERE product = 'TENNIS RACKET';
        INSERT INTO purchase_record
            VALUES ('Tennis racket purchased', SYSDATE);
    ELSE
        INSERT INTO purchase_record
            VALUES ('Out of tennis rackets', SYSDATE);
    END IF;

    COMMIT;
END;
/
