mysql - 查找 > 0 的最小值，也没有负值

Question

我想从 MySQL 读取一行，它返回平均值、std dev pop 和最大值以及分钟。

基本上，我想从特定表中获取 MIN，但不是 0，或任何小于 0 的值。

我试过了

MIN(NULLIF(`stock_qty`, 0)) AS `stock_qty`,

作为 SELECT 参数，但仅当 MIN 为 0 时才返回 null

我当前的方法如下:

SELECT 
    MAX(`stock_qty`) AS `stock_qty_max`,
    MIN(`stock_qty`) AS `stock_qty_min`,
    AVG(`stock_qty`) AS `stock_qty_avg`,
    STDDEV_POP(`stock_qty`) AS `stock_qty_std`,
    SUM(`stock_qty`) AS `stock_qty_sum`,
    MAX(`adjusted_online_set`) AS `adjusted_online_set_max`,
    MIN(`adjusted_online_set`) AS `adjusted_online_set_min`,
    AVG(`adjusted_online_set`) AS `adjusted_online_set_avg`,
    STDDEV_POP(`adjusted_online_set`) AS `adjusted_online_set_std`,
    SUM(`adjusted_online_set`) AS `adjusted_online_set_sum`,
    COUNT(*) AS `count`
FROM
    `cat_product` AS `prod`
        LEFT JOIN
    `cat_position` AS `pos` ON pos.product_id = prod.product_id
        RIGHT JOIN
    `cat_product_website` AS `pweb` ON pos.product_id = pweb.product_id
WHERE
    (pos.category_id = '8476')
    AND ((prod.adjusted_online_set > 0) OR (prod.stock_qty > 0))

但这也会为两个字段返回负值。

Answer 1

分钟(案件 当stock_qty > 0 那么stock_qty 否则为空结尾) AS stock_qty