Comments

/* First find out if the database we want to create exists already */

A comment can also be spread on more than one line, like a paragraph. Here is an example:

/* First find out if the MotorVehicleDivision database we 
   want to create exists already.
   If that database exists, we don't want it anymore. So,
   delete it from the system. */

Transact-SQL also supports the double-dash comment. This comment applies to only one line of text. To use it, start the line with --. Anything on the right side of -- is part of a comment and would not be considered as code. Here is an example:

-- =============================================
-- Database: MotorVehicleDivision
-- =============================================

/* First find out if the MotorVehicleDivision database we 
   want to create exists already.
   If that database exists, we don't want it anymore. So,
   delete it from the system. */


-- Now that the database is not in the system, create it

In SQL, after writing a statement, you can end it with a semi-colon. In fact, if you plan to use many statements in one block, you should end each with a semi-colon. When many statements are used, some of them must come after others.

To separate statements, that is, to indicate when a statement ends, you can use the GO keyword (in reality and based on SQL standards, it is the semi-colon that would be required, but the Microsoft SQL Server interpreter accepts GO as the end of a statement).