Selecting most recent date between two columns

Question

If I have a table that (among other columns) has two DATETIME columns, how would I select the most recent date from those two columns.

Example:

Answer 1

CASE is IMHO your best option:

SELECT ID,
       CASE WHEN Date1 > Date2 THEN Date1
            ELSE Date2
       END AS MostRecentDate
FROM Table

---

If one of the columns is nullable just need to enclose in COALESCE:

.. COALESCE(Date1, '1/1/1973') > COALESCE(Date2, '1/1/1973')

Answer 2

I think the accepted answer is the simplest. However, I would watch for null values in the dates...

SELECT ID,
       CASE WHEN ISNULL(Date1,'01-01-1753') > ISNULL(Date2,'01-01-1753') THEN Date1
            ELSE Date2
       END AS MostRecentDate
FROM Table

Answer 3

select ID, 
case
when Date1 > Date2 then Date1
else Date2
end as MostRecentDate
from MyTable

Answer 4

select ID,(select max(d) from (select Date1 d uninon select Date2 d) as t) as MaxDate
from MyTable

Answer 5

AFAIK, there is no built-in function to get the maximum of two values, but you can write your own easily as:

CREATE FUNCTION dbo.GetMaximumDate(@date1 DATETIME, @date2 DATETIME)
RETURNS DATETIME
AS
BEGIN
    IF (@date1 > @date2)
        RETURN @date1
    RETURN @date2
END

and call it as

SELECT Id, dbo.GetMaximumDate(Date1, Date2)
FROM tableName

Answer 6

This thread has several solutions. If you had more than 2 dates to compare, "unpivot" might be preferable to writing a series of case statements. The following is blatantly stolen from Niikola:

select id, max(dDate) MostRecentDate
  from YourTable
    unpivot (dDate for nDate in (Date1, Date2, Date3)) as u
  group by id 

Then you can order by dDate, if that's helpful.