How to truncate log file in SQL Server 2008

Background

In SQL Server data is stored using two physical files:  

1. (.mdf)  extension  which contains the data. 
2. (.ldf) extension which contains log. 

Log file size increases very rapidly and depend on the operation performed on the data. After a long time period this file becomes too large. When log file is too large it takes time to perform some operations like ( attach , de-attach, backup, restore ... etc ).  

Using the code

Step 1. Copy/type the below given SQL.

Step 2. Change @DBName to < Database Name>, @DBName_log to <Log File Name> 

Step 3. Execute the SQL. 

ALTER DATABASE @DBName SET RECOVERY SIMPLE WITH NO_WAIT
DBCC SHRINKFILE(@DBName_log, 1)
ALTER DATABASE @DBName SET RECOVERY FULL WITH NO_WAIT
GO