Question

我有以下查询：

SELECT id, title, adcontent, adtargetURL, locationpage, 
locationarg, locationid, displayorder, visible, schedstart, 
schedstop, created, modified, createdby, modifiedby
FROM ads            
ORDER BY locationpage, locationarg, locationid, title

我需要按以下方式订购字段：

按位置排序，首先使用值为'all'的任何字段，然后按升序排列其余字段
然后通过locationarg首先使用任何NULL或空字符串值，然后将其余部分保存在asc
然后通过locationid首先使用任何NULL或0值，其余部分在asc
并在其中，首先按“1”的displayorder排序，然后按NULL，然后按“2”
最后，如果其中任何一个都是相同的，则按ASC中的标题

我的ORDER BY应该如何实现这一目标？

这是我到目前为止所做的:(从下面更新）

ORDER BY locationpage='all', 
         locationpage ASC, 
         locationarg ASC, 
         locationid ASC, 
         displayorder='1', 
         ISNULL(displayorder), 
         displayorder='2', 
         title ASC

......但这不起作用！

Answer 1

您最好的选择是使用一个计算字段，根据您的规则生成订单ID。我稍后会添加一个示例..

select
case
  when locationpage = "all" then 10
  when ISNULL(locationarg)  then 20
  ....
  else 50 
end as OrderID,
id, 
title, 
....

FROM ads            

ORDER BY OrderID DSEC

Answer 2

给这个打击：

select id, title, adcontent, adtargetURL, locationpage, locationarg, locationid, displayorder, visible, schedstart, schedstop, created, modified, createdby, modifiedby 
from ads
order by case when locationpage='all' then 0 else 1 end, 
         locationpage, 
         case when locationarg is null or locationarg='' then 0 else 1 end,
         locationarg ASC, 
         case when locationid is null OR locationid='0' then 0 else 1 end, 
         locationid, 
         case when displayorder =1 then 0 when displayorder is null then 1 when displayorder = 2 then 2 else 3 end,
         title;

带有复杂ORDER BY的MySQL查询

2 个答案: