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

As @Forte L. mentioned you can do the following as well;

SELECT dtCreated
    , bActive
    , dtLastPaymentAttempt
    , dtLastUpdated
    , dtLastVisit

    , DATEDIFF(day, dtCreated, dtLastUpdated) Difference

FROM Customers
WHERE (bActive = 'true') 
    AND (dtLastUpdated > CONVERT(DATETIME, '2012-01-0100:00:00', 102))

Answer 2

DATEDIFF(d, 'Start Date', 'End Date')

do it

Answer 3

You would use DATEDIFF:

declare @start datetime
declare @end datetime

set @start = '2011-01-01'
set @end = '2012-01-01'

select DATEDIFF(d, @start, @end)

results = 365

so for your query:

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