sql从列计算日期

Question

Hi I need a bit of advice with the following question which reads as follows: Provide the sql that will determine the length of employment for each employee. For each employee display lastname and calulate number of years between today and the date on which the employee was hired. Label the column 'YEARS'

Im not sure how to approach this, should I use the datediff() function? Can I do something like this:

SELECT DATEDIFF(HIRE_DATE,'2014-09-29') AS DiffDate 

Also how do I format DiffDate then that the output will only be years?

Thanks

Answer 1

use as

SELECT LastName, DATEDIFF('day',HIRE_DATE,'2014-09-29') AS DiffDate from TableName

I am assuming that Table contains LastName column.

Reference

Answer 2

The correct syntax for DATEDIFF could be found here http://msdn.microsoft.com/en-us/library/ms189794.aspx

SELECT DATEDIFF(day, HIRE_DATE,'2014-09-29') AS DiffDate 
From yourtable