how to get the number on months between two dates in sql server 2005

Question

I have a column in my sql server 2005 table that should hold the number of months an employee has been in service.

Since I also have the date the employee was engage

Answer 1

If You presume that month is meaning for 30 days You can also round vale

round((datediff(day,[DateEngaged],getdate()))/30.00,0)

Answer 2

Maybe you want something like:

(year(getdate())-year([DateEngaged]))*12+(month(getdate())-month([DateEngaged]))

Answer 3

Something like (might need to swap the 1 and 0, untested)

datediff(month,[DateEngaged],getdate()) +
 CASE WHEN DATEPART(day, [DateEngaged]) < DATEPART(day, getdate()) THEN 1 ELSE 0 END

DATEDIFF measure month boundaries eg 00:00 time on 1st of each month, not day-of-month anniversaries

Edit: after seeing OP's comment, you have to subtract 1 if the start day > end day

DATEDIFF (month, DateEngaged, getdate()) -
 CASE
   WHEN DATEPART(day, DateEngaged) > DATEPART(day, getdate()) THEN 1 ELSE 0
 END

So for 20 Dec to 13 Jan, DATEDIFF gives 1 and then 20 > 13 so subtract 1 = zero months.

Answer 4

Same approach as gbn, but with less keystrokes :-)

SELECT 
    DATEDIFF(MONTH, DateEngaged, GETDATE()) +
    CASE 
        WHEN DAY(DateEngaged) < DAY(GETDATE())
        THEN 1 
        ELSE 0 
    END