Create and alter database

To create the database using a query

Create database DatabaseName

To alter a database, once it's created 

Alter database DatabaseName Modify Name = NewDatabaseName

Or

sp_renameDB 'OldDatabaseName','NewDatabaseName'

Creating database with file groups

CREATE DATABASE [FGTest] ON  PRIMARY

( NAME = N'exampledb',

FILENAME ='E:\sample.mdf' ,

SIZE = 3072KB , FILEGROWTH = 1024KB ),

FILEGROUP [Secondary] ( NAME ='exampledb2',

FILENAME = N'E:\sampledb2.ndf' ,

SIZE = 3072KB , FILEGROWTH = 1024KB )

LOG ON

( NAME = N'Example_log',

FILENAME = N'E:\example_log.ldf' ,

SIZE = 1024KB , FILEGROWTH = 10%)

GO

To Delete or Drop a database

You cannot drop a database, if it is currently in use.

So, if other users are connected, you need to put the database in single user mode and then drop the database.

Alter Database DatabaseName Set SINGLE_USER With Rollback Immediate

drop database databasename