What is a null?

The word null or DG is a much managed term in the science of computing, which refers to anything that is an undefined value.


In the area of programming, is the result of a diligent special value to a pointer used to show that the pointer does not fit to a valid data. The value 0 is commonly used “zero” to define null, this is because most operating systems assume the try to adhere to a memory address low as if it were a mistake.

Similarly, results for logical operations are required:

Operation “Or” or “OR”

True or null = true

False or null = 0

Operation “And” or “AND”

True and null = 0

False and null = false

Is also used in other areas and is not a unique term of programming.

In scope of the databases the term null is used to show the absence of a value Assembly to a field for a particular record in the tables.

What programming languages use this term?

Almost all it is a term which as already mentioned indicated the absence of a value.

Would that other disciplines to use this term?

In all those requiring store information or analysis, for example medicine, crimino-ology, statistics, etc.

What is null in SQL?

It is a special term used in structured query language (SQL) to show that a value or data in a database there is. This was done by the author of the relational model of databases.