So as an alternative to SUMIF or COUNTIF or SUMIFS or COUNTIFS Functions, we can look at D Functions instead. And D Functions have some advantages over the more simple SUMIF or SUMIFS Functions. So let's have a look at them first, and then we'll talk about perhaps, some of the advantages they have. So the first thing is, unlike the SUMIF or SUMIFS Functions, the criteria aren't built into the function itself. Rather a bit like when we run an advanced filter, we have to set up an area of the spreadsheet first, where we're gonna enter the criteria that we're gonna use for our D Functions. So that's what we're gonna do first. And I'm gonna literally just copy the Column Headings from my database and just copy them into a new area of the spreadsheet, just at the top here. Just underneath the question that this, our first question that is posed to us. It's asking us, "How many units of lip gloss has Ashley sold?" Okay, so this is what I need to build up in my criteria. It's the criteria that I want to add in to match the question that's being asked. So, "How many units of lip gloss has Ashley sold?" So lip gloss. (keyboard clicking) Ashley. So there's my criteria.

The next stage then is to actually write the function itself.

So let's just come on up here, and this is where we're gonna put our total. So we start off, all the functions in the D Function Range are exactly the same. There's just the letter D preceding the normal function name. So it's asking us, "How many units?" So this is gonna be a SUM. So we want a DSUM.

(space bar clicking) And they all have the same three arguments as well. So this another nice thing about the D Functions, is they all follow the nice, same pattern. So the first argument's always the database and that includes the Column Headings. So I'm gonna come down here, and then we're gonna select the whole thing, including the Column Headings. The second one is the field that I want to do the calculation on. So it's asking us about the units that are sold. So I just come down. And notice, I'm just selecting the Column Heading. So just the Units. I don't have to select the whole column, it's just the Units at the top. Comma. And then the criteria is the whole criteria section that I set up in my spreadsheet at the top.

So it's just that area there. Close the brackets, press Enter. So, "How many units of lip gloss has Ashley sold?" 1,985.

Let's have a look at the next one. We've got, "What was the average units sold by Ashley in the south?" Okay, so let's just copy our headings down again. (keyboard clicking) So we still want Ashley.

So we can copy that in there. But this time, it's asking us about the south region.

And it's asking as to the average units sold. So equals, D, AVERAGE.

Same three arguments, you'll notice. The database first. So it's coming down to the database. (keyboard clicking) Comma. The fields that we wanted to use. So it's still asking us about Units. So it's the Units header only. Comma. And then the final piece then is the criteria. And that's all of the section that we've just built at the top here. Close the brackets, press Enter. So the, "Average unit sold by Ashley in the south," 41.8.

So hopefully, now you can see after doing a couple of D Functions, they all follow the same pattern. So just remember you can have DCOUNT, DAVERAGE, DSUM, DMIN, DMAX, and a number of other D Functions. The nice thing about them, is they all follow the same pattern. And obviously, if I change the criteria in the Criteria Section, my formulas automatically update in real-time. They're very quick, very fast, and they're a neat way of extracting calculation information from a database. Okay, so that's it for D Functions. I'll leave you to answer that last question, "What was Ashley's biggest sale in 2013?" I'll leave you that one to figure out on your own. Good luck.