Re: To function or not to function, that is the question at hand

Mike,

My experience with SQL functions is limted (just made one), but I am not
thrilled by it. The main reason: a terrible performance at times, something
I would not present to my users. And the function would be called for each
row it fetches and may return in your result set.

If you do this only for building the start date and end date, I would use a
CTE, if possible, so that has to be done only once.

Just my 2 cents.

With regards,
Carel Teijgeler


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On 9-2-2011 at 15:39 Mike Wills wrote:

I am working on some SQL statements for an ASP.NET application. One of the

things that is required is to only display information in an open period.

The period is updated automatically by the vendor software as the previous

period is closed. So I finding myself doing a bunch of sub selects like:

where date >= (SELECT DATE(CONCAT('20', CONCAT(YY, CONCAT('-', CONCAT(

MM, (CONCAT('-', DD))))))) FROM LIB/FILE')

Yes, each portion of the date is in separate fields.

Would making this query a function make the query more efficient? I have

never created a function before how would I do that? My thought is having

something like:

IsInRange(date)

So I can do "WHERE IsInRange(date)".

Or is there a better way?