Questions

Using automatically incrementing IDENTITY columns is very popular with database developers. You don’t need to explicitly calculate unique surrogate keys when inserting new data, the IDENTITY column functionality does that for you. The IDENTITY feature also allows you to specify useful Seed and Increment properties. When you use an INSERT statement to insert data into a table with an IDENTITY column defined, SQL Server will generate a new IDENTITY value.

You can use the @@IDENTITY variable and the SCOPE_IDENTITY and IDENT_CURRENT functions to return the last IDENTITY value that has been generated by SQL Server. This is very useful when you need to return the key for the row that has just been inserted, back to the caller.

The simplest form of matter that has a unique set of properties and is cannot be broken down into simpler substances by chemical means is called an Element.

An Atom is the simplest form of an element.

The simplest form of some elements is a Molecule. When an element consists of two identical atoms it is called a diatomic molecule.

A substance that contains two or more elements chemically combined in a fixed proportion is called a Compound.