例9（例外処理）
この例は、EXCEPTIONを上げる方法を示しています。
PROCEDURE exception_example (OUT has_error INT)
BEGIN
DECLARE too_many_categories EXCEPTION;
DECLARE no_categories EXCEPTION;
DECLARE category_count INT DEFAULT 0;
SELECT COUNT(Categories.CategoryName) INTO category_count
FROM /shared/access/Categories Categories;
IF category_count > 5 THEN
RAISE too_many_categories;
ELSEIF category_count = 0 THEN
RAISE no_categories;
END IF;
SET has_error = 0;
EXCEPTION
WHEN too_many_categories OR no_categories THEN
SET has_error = 1;
END