I work primarily on SQL Server these days but I had originally started learning SQL on Oracle. I find the sample tables EMP, DEPT, BONUS, SALGRADE and DUMMY provided with Oracle to be useful for beginners to practice SQL commands. Oracle provides the script by the name of DEMOBLD.SQL to create these tables which can be found in the <OracleHome>sqlplusdemo folder of your Oracle installation or at this URL. Some more useful scripts for Oracle users can be found at this OraFAQ page.
I thought that few folks might like to have those tables on SQL Server so I made some changes to the script so that it can run on SQL Server too. It might prove useful if you don’t have access to an Oracle installation but want want to practice SQL commands with these tables. Of course, MS SQL Server does not support all the SQL syntax as supported by Oracle, but the tables can be handy in some cases.
The SQL Server compatible script is at the TechNet link below. The basic difference from the original script is in the datatypes and the datetime convert function. The script will drop any tables with the same names in the current database so be sure that existing tables do not have any critical data.