我不知道这在 SQL 中是否可行,或者我是否必须编写存储过程,但我正在尝试使用 ISNULL 函数,如下所示,以便当参数 @sku 为 null 时,我使用 select 语句带来返回表中的所有 sku:
SELECT GooglePrice.idGooglePrice, GooglePrice.idProduct, products.sku, products.wholeprice, products.price as CurrentHMMPrice, GooglePrice.bestPrice, GooglePrice.link, GooglePrice.title, GooglePrice.description, GooglePrice.ourPrice as PriceCompHMMPrice,
GooglePrice.searchType, GooglePrice.shippingCost, GooglePrice.cheapestOrder, GooglePrice.timeStamp,
'ShippingCostNew' = CASE
WHEN GooglePrice.shippingCost = -1 THEN 'N/A'
WHEN GooglePrice.shippingCost = 0 THEN 'Free Shipping'
WHEN GooglePrice.shippingCost > 0 Then cast(GooglePrice.shippingCost as varchar)
END
FROM GooglePrice INNER JOIN
products ON GooglePrice.idProduct = products.idProduct
WHERE (products.supplierCode in (@SupplierCode)) AND ISNULL((products.sku like '%'+@sku+'%'), (products.sku in (select sku from products where products.sku)))
ORDER BY GooglePrice.idGooglePrice