What Is SQL guides beginners, experts, and intermediate readers through the most important aspects of declarative and procedural SQL. Knowledge gained includes the following: Designing, building, and querying relational databases in the latest versions of oracle and SQL server databases Performing data-quality operations that eliminate corrupted data from databases Extending the functionality of SQL using PL/SQL and programmable T-SQL Building and loading data warehouses without using an expensive ETL tool Troubleshooting and tuning SQL code and database designs Extensive use of built-in functions to retrieve and transform data Translating complex business rules into database constraints Creating advanced queries that answer complex business questions Manipulating data within tables Creating recoverable business transactions Perform nonstandard SQL operations such as deleting duplicate rows Obtain a free sample of oracle11i and SQL server 2012 databases. Это и многое другое вы найдете в книге What Is SQL ?. Fundamentals of SQL, T-SQL, PL/SQL and Datawarehousing (Victor Ebai)