How to find the number of days between two dates

Question

I have a basic query:

SELECT dtCreated
    , bActive
    , dtLastPaymentAttempt
    , dtLastUpdated
    , dtLastVisit
FROM Customers
WHERE (bActive = \'true\         


        

Answer 1

I would use the DATE_DIFF function to provide this value as below:

SELECT dtCreated
    , bActive
    , dtLastPaymentAttempt
    , dtLastUpdated
    , dtLastVisit
    , DATEDIFF(d, dtLastUpdated, dtCreated) AS Difference
FROM Customers
WHERE (bActive = 'true') 
    AND (dtLastUpdated > CONVERT(DATETIME, '2012-01-0100:00:00', 102))

EDIT: IF using MySQL you omit the 'd' leaving you with

DATEDIFF(dtLastUpdated, dtCreated) AS Difference