Adventure Works sample databases for SQL Server 2012 is available for download from the following link
http://msftdbprodsamples.codeplex.com/releases/view/55330
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There are also different kinds of database samples are also available like
AdventureWorksDW2012 Data File
AdventureWorks Multidimensional Models SQL Server 2012
Analysis Services Tutorial SQL Server 2012
AdventureWorks Tabular Model SQL Server 2012
AdventureWorks Internet Sales Tabular Model SQL Server 2012
AdventureWorks 2012 CS OLTP Script
AdventureWorks 2012 OLTP Script
AdventureWorks2012 CS Data File
AdventureWorks 2012 LT Script.zip
AdventureWorks2012-Full Database Backup.zip online casino slots