将一列置于另一列之上

CREATE TABLE logistics ( id int primary key, campaign VARCHAR(255), quantity_offered VARCHAR(255), quantity_ordered VARCHAR(255), quantity_delivered VARCHAR(255), quantity_recorded VARCHAR(255), quantity_completed VARCHAR(255));INSERT INTO logistics(id, campaign,quantity_offered, quantity_ordered, quantity_delivered,quantity_recorded, quantity_completed)VALUES("1", "C001", "500", "450", "465", "462", "465"),("2", "C002", "700", "570", NULL, NULL, NULL),("3", "C003", "600", "610", "605", "602", NULL),("4", "C004", "300", NULL, NULL, NULL, NULL),("5", "C005", "400", "425", NULL, NULL, NULL),("6", "C006", "900", "870", "868", NULL, NULL),("7", "C007", "350", "360", "372", "375", "390"),("8", "C008", "250", "290", NULL, NULL, NULL);在上表中，我有不同的 campaigns 及其对应的 quantities.quantities 填入不同的列.In the table above I have different campaigns with their corresponding quantities.The quantities are filled in different columns.现在，我想根据以下层次结构获取每个广告系列的最新可用数量:Now, I want to get the latest available quantity for each campaign based on the following hierarchy:quantity_completed > quantity_recorded > quantity_delivered > quantity_ordered > quantity_offered结果应该是这样的:Campaign QuantityC001 465C002 570C003 602C004 300C005 425C006 870C007 390C008 290我需要什么查询来实现这一点?What query do I need to achieve this?推荐答案使用 coalesce():select campaign, coalesce(quantity_completed, quantity_recorded, quantity_delivered, quantity_ordered, quantity_offered) as quantityfrom logistics; 这篇关于将一列置于另一列之上的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！