mysql - 如何最后订购没有库存的商品

Question

我有以下 MySQL 查询:

SELECT
    *
FROM
    product
INNER JOIN productcontent ON product.id = productcontent.productID
WHERE
    product.deactivate <> '1'
AND productcontent.price > 0 { $level1SQL }
AND menulevel IN ($imploded)
OR menulevel = '$menulevelID' { $level1SQL }
ORDER BY
    (
        CASE
        WHEN discountPrice < price
        AND discountPrice > 0 THEN
            CAST(
                discountPrice AS DECIMAL (10, 2)
            )
        ELSE
            CAST(
                price AS DECIMAL (10, 2)
            )
        END
    ) { $price_order }
LIMIT { $limit }

但我还需要确保，如果 product.notInStock 设置为 1，则在最后订购(但仍按名称/价格，如果选择这样的排序)，是否有可能，或者我应该只使用 2 个查询 - 一个用于有库存的产品，一个用于没有库存的产品？

Answer 1

您可以向 ORDER BY 添加一个附加键:

SELECT *
FROM product p INNER JOIN 
     productcontent pc
     ON p.id = pc.productID
WHERE p.deactivate <> '1' AND
      pc.price > 0 {$level1SQL} AND
      (menulevel IN ($imploded) OR menulevel = '$menulevelID')
      {$level1SQL}
ORDER BY p.not_inStock DESC,
         (case when discountPrice < price and discountPrice > 0
               then CAST(discountPrice AS DECIMAL(10,2))
               else CAST(price AS DECIMAL(10,2)) 
          end) {$price_order}
LIMIT {$limit}

此外，menulevel 上的最后一个条件表明您需要括号。