What is a NULL Value?

In simple English, NULL means nothing – absolutely nothing. In MS Access too, NULL means the same….no Value. NULL means absence of any value whatsoever. NULL is different from a zero Value. In fact, NULL is also different from a Zero length String (ZLS), though they appear the same visually.

The presence of NULL value indicates that maybe you have no value to add in the table, or simply the value is unknown. Furthermore, you cannot compare NULL value i.e. Comparing two NULL value will give you NULL, since by definition you have no value to compare with.

6 Logical Operators in MS Access that you must know [Operator Types 3 of 5]

While doing any data analysis, you often encounter situations wherein you need to make use of Boolean logic. Now, Boolean logic involves operations on Truth values TRUE (1) and FALSE values (0) .

In simple words, you would be interested, at times, in knowing the output when one expression is true and(/or) second expression is also true. You can think of Boolean logic as a  simple way of comparing individual inputs and expressions. In order to make those comparisons, it uses what are called as operators aka “Logical Operators”.  Note that Boolean logic is a form of logic that reduces all values to either TRUE or FALSE.

In this post, you are going to learn about Logical Operators in MS Access. You will make use of logical operators to combine two expressions and return a value of “TRUE”, “FALSE”, or “NULL” depending on the Boolean value of the expression on which logical operation is being done.

6 Comparison Operators in MS Access that you need to know about [Operator Types 2 of 5]

In this post you’ll learn how and when to use the comparison Operator. As the name suggests, comparison operator allows you to perform comparison between two operands.

7 Useful Arithmetic Operators in MS Access that you should know [Operator Types 1 of 5]

As discussed in the earlier post ‘Applying Criteria in MS Access’, you will now be using and analyzing  in details the various operators that are available in MS Access. In this post you will learn the basics of arithmetic operator.

Applying Criteria in MS Access

In this post and the ones following next, you are going to learn how to filter the data so as to get the exact information that you want. So, what exactly is filtering the data? – Filtering means separating out or pulling out the ‘required information’ from the base data. Note that you need to know beforehand “what exactly is required”. And in order to get “what is required”, you need to specify certain rules or conditions that must be met. Such rules or conditions are known as “Criteria” and there are different ways of specifying this criteria. Let us see how this is done…..

Sorting the Final Result in MS Access

Once you create a query, you are sometimes required to apply a sort on the final result. The sort could either be in an ascending order or descending order. It can be achieved in the following way in MS Access…..

MS Access Query – What is it anyway?

What’s a query by the way? As you can see, it literally means asking a question to the dataset so that you get the desired reply. Now, just as in real life, the nature of the reply depends on the type of the ‘query’ you ask as well as the way you ask it i.e. how you ask it.
 

…..And this is just what we are going to learn today…So let’s begin..