Getting Started with the Microsoft Access Expression Builder

All right, so what exactly is an expression? What is this expression builder building? Well, an expression is something that Access can evaluate to get an answer.

The answer might be a number, some text, a date, a yes or no value, and other stuff.

Let's say one order line has a unit price of $10 and a quantity of three.

You multiply those together, you get $30.

That's an expression.

Access takes the values from that record and then works out the answer.

And the next record could have a different price and quantity so it gets its own answer.

You can also do things like concatenation.

You can put first name and last name together, or you can compare a due date with today's date.

The expression builder helps you write those instructions, but you still decide what you want the answer to mean.

Now, why use the builder? I'll be the first to admit I almost never use the expression builder for myself anymore.

I've been working with Access for over 30 years, and it's usually faster for me to type the expression directly.

But when you're learning, it's helpful to see what you've got available.

You don't have to remember the name of every function.

You can browse through a list, read what the function does, and let Access help you with the syntax.

It's also useful for references to controls on forms.

You might know you want the customer's first name from that form over there, but not how to spell out the whole thing.

Me, for example, I always forget what I name forms when I name the controls.

So sometimes I'll pop into the expression builder because it gives you what all the names of the forms and the controls are.

And that's exactly what our second example is going to show.

Even if you're comfortable with typing expressions, you can still come back here when you need to look something up.

I sometimes do.