CREATE DATABASE in default path - sql-server

Question

I have simple code
: CREATE DATABASE [asst]
: ON (NAME = 'asst_dat', FILENAME = 'C:\data' , SIZE = 62, FILEGROWTH = 10%)
: LOG ON (NAME = 'asst_log', FILENAME = 'C:\data' , SIZE = 146, FILEGROWTH = 10%)
How can I change the FILENAME parameter to create DB in the default installation path like C:\Program Files\Microsoft SQL Server\MSSQL10_50.ATASSIST\MSSQL. So why I need it: from version to version, from instance to instance of SQL Server this locations differs

Answer 1

First create the database and then alter file properties as needed.
CREATE DATABASE [DBName]
GO
ALTER DATABASE [DBName] MODIFY FILE
( NAME = N'DBName' , SIZE = 512MB , MAXSIZE = UNLIMITED, FILEGROWTH = 1024KB )
GO
ALTER DATABASE [DBName] MODIFY FILE
( NAME = N'DBName_log' , SIZE = 256MB , MAXSIZE = UNLIMITED , FILEGROWTH = 10%)
GO

Answer 2

You can use the following variables, that respectively contain the root directory of your install and the data directory :
SELECT ##basedir, ##datadir;

Answer 3

Thanks, überjesus, I've simplified your code a little bit
DECLARE #rows varchar(MAX),
#script nvarchar(MAX);
SET #rows = (SELECT physical_name AS current_file_location
FROM sys.master_files
where name = 'master');
SET #rows = Replace(#rows, 'master.mdf', '')
SELECT #rows;
set #script = 'CREATE DATABASE [assist1]
ON (NAME = ''asst_dat'', FILENAME = ''' + #rows + 'assist1.mdf'' , SIZE = 62, FILEGROWTH = 10%)
LOG ON (NAME = ''asst_log'', FILENAME = ''' + #rows + 'assist1_log.ldf'' , SIZE = 146, FILEGROWTH = 10%);'
exec(#script);
Thanks for a great idea!

Answer 4

try this
You can create a database without specifying file details, like:
CREATE DATABASE DatabaseName;

Answer 5

Assuming you are using SQL Server 2005 or 2008 this should do it. Although it's probably a bit longer than you expected :-) You could put the main part of the code into a function and call that every time you need to create a database.
declare #instance_name nvarchar(200),
#system_instance_name nvarchar(200),
#registry_key nvarchar(512),
#path_data nvarchar(260),
#path_log nvarchar(260),
#value_name nvarchar(20),
#script nvarchar(4000);
set #instance_name = coalesce(convert(nvarchar(20), serverproperty('InstanceName')), 'MSSQLSERVER');
exec master.dbo.xp_regread N'HKEY_LOCAL_MACHINE', N'Software\Microsoft\Microsoft SQL Server\Instance Names\SQL', #instance_name, #system_instance_name output;
set #registry_key = N'Software\Microsoft\Microsoft SQL Server\' + #system_instance_name + '\MSSQLServer';
/* determine default location for data files */
exec master.dbo.xp_regread N'HKEY_LOCAL_MACHINE', #registry_key, N'DefaultData', #path_data output;
if #path_data is null
begin
/* this is only executed if we are using the default instance */
set #registry_key = N'Software\Microsoft\Microsoft SQL Server\' + #system_instance_name + '\Setup';
exec master.dbo.xp_regread N'HKEY_LOCAL_MACHINE', #registry_key, N'SQLDataRoot', #path_data output;
set #path_data = #path_data + '\Data';
end;
/* determine default location for log files */
exec master.dbo.xp_regread N'HKEY_LOCAL_MACHINE', #registry_key, N'DefaultLog', #path_log output;
if #path_log is null
begin
/* this is only executed if we are using the default instance */
set #registry_key = N'Software\Microsoft\Microsoft SQL Server\' + #system_instance_name + '\Setup';
exec master.dbo.xp_regread N'HKEY_LOCAL_MACHINE', #registry_key, N'SQLDataRoot', #path_log output;
set #path_log = #path_log + '\Data';
end;
set #script = 'CREATE DATABASE [asst]
ON (NAME = ''asst_dat'', FILENAME = ''' + #path_data + '\yourfile.mdf'' , SIZE = 62, FILEGROWTH = 10%)
LOG ON (NAME = ''asst_log'', FILENAME = ''' + #path_log + '\yourfile.ldf'' , SIZE = 146, FILEGROWTH = 10%);'
exec(#script);
You can not use variables in the CREATE DABASE statement. That's why you have to create a variable that holds the command and execute that as a script.