SQL：在计算值上使用Max（）选择多个列

Question

Real basic: I have table T with following data:

ID   StartDate  Term (months)
----------------------
1    10/1/2012   12
2    10/1/2012   24
3    12/1/2012   12

I need to know the ID of the row that has the max end date. I've successfully calculated the end date as select max( DateAdd(month, term, StartDate) from table [this would result in 10/1/2014]

how do i get the ID value and Start Date of the row that contains the max end date?

Answer 1

MS SQL:

SELECT TOP 1 ID, StartDate
FROM T
ORDER BY DateAdd(month, term, StartDate) DESC

MySQL:

SELECT ID, StartDate
FROM T
ORDER BY DateAdd(month, term, StartDate) DESC
LIMIT 1

Answer 2

In case more than one ID has the same extreme "end date" and you need them all, you can try this:

SELECT x.id
FROM (
   SELECT id
        , RANK ( ) OVER ( ORDER BY  DateAdd(month, term, StartDate) DESC) as rn
   FROM T
   ) x
WHERE t.rn = 1