Question

I have a MySQL table Page with 2 columns: PageID and OrderByMethod.
I also then have a Data table with lots of columns including PageID (the Page the data is on), DataName, and DataDate.

I want OrderByMethod to have one of three entries: Most Recent Data First, Most Recent Data Last, and Alphabetically.

Is there a way for me to tack an “ORDER BY” clause to the end of this query that will vary its ordering method based on the contents of the “OrderByMethod” column? For example, in this query, I would want to have the ORDER BY clause contain whatever ordering rule is stored in Page 1’s OrderByMethod column.

GET * FROM `Data` WHERE `Data`.`PageID`=1 ORDER BY xxxxxx;

Maybe a SELECT clause in the ORDER BY clause? I’m not sure how that would work though.

Thanks!

Answer 1

select Data.* 
from Data
inner join Page on (Data.PageID=Page.PageID)
where Data.PageID=1
order by 
if(Page.OrderByMethod='Most Recent Data First', now()-DataDate, 
  if(Page.OrderByMethod='Most Recent Data Last', DataDate-now(), DataName)
);