How do you carryout calculations in ms access?

Answer 1

Yes. This is mainly done through queries, but can also be done in forms and reports. A lot of databasing is based on doing calculations on stored data. A general rule on databases is that you do not store anything that can be calculated from existing data. So if you are storing dates of birth, there is no need to store ages, as the age of someone can always be calculated from their date of birth. Also, an age won't change if you literally type it into a database. So if you typed in someone's age into a database and did not look at it for a few years, the next time you open it, the person's age would still show the same as when you typed it in. Whereas if you have their date of birth stored, you can always calculate their age immediately with a simple calculation, on a form or a report or a query. Once you have today's date, which can be got direct from your computer, and a date of birth, it is easy to calculate an age.

The same idea would apply with things like wages or tax. All you need are the base values and once you have those you can get the database to do the calculations to find the figures you need. If you have a wage and a tax rate, or the amount of hours someone has worked and the rate per hour, you can calculate the pay from those, so the pay doesn't necessarily have to be stored. To the end user who will see the output, it will look like the data is actually there, but it isn't and doesn't need to be. So if something can be calculated using the data you already have, then do it as a calculation when a query is run, a form or report opened, rather than storing it unnecessarily. There will be times when you need to store calculated data, but more often that not, it doesn't need to be. So as you can see, calculations are very important in databases and the facilities are there to use them.

Answer 2

You can do them in lots of ways. You can do them in formulas similar to Excel. Instead of referring to cells, you refer to field names. You can do this in queries or in forms or reports etc. You can use the Expression Builder to actually write them.