Is It Possible To Use Values From Another Table As The Interval In A DATEADD Function?

I have a table of events containing a date (smalldatetime). I have a table of intervals (int) (days before) for when a reminder should be sent - DATEADD(D, *interval*, GETDATE()).

Solution 1:

Yes. You should have tried it yourself

create table t(val int);
insert into t values(4),(7),(10)

select DATEADD(D, val, GETDATE()) from t

SQLFiddle

Solution 2:

The answer is yes. I can't draw this query for you due to lack of information provided. But yes, you can.

Take this example:

MyTable:
ID    Interval    Date
1     1           10-10-2001

SELECT ID, DATEADD(D, Interval, GETDATE()) AS NewDate FROM MyTable


SELECT e.*
FROM [events] e
INNER JOIN [interval] i on e.customerID = i.customerID
WHERE e.date = DATEADD(D, i.daysBefore, 
                   DATEADD(D, 0, 
                       DATEDIFF(D, 0, GETDATE())))

Solution 3:

Thanks everyone for showing how that's possible. I presume this would be how to write the SQL, unless there is a more efficient way?

SELECT *
FROM events
WHERE date IN (
    SELECT DATEADD(D,daysBefore,DATEADD(D, 0, DATEDIFF(D, 0, GETDATE())))
    FROM interval
    WHERE events.customerID = customerID);

SQLFiddle