Database theory and an online tutorial interface to an Oracle database system, allowing a user to learn SQL interactively. The site automatically checks and marks SQL and gives instant feedback.
Help everyone to gain or improve skills in building SQL Data Manipulation Language statements. A rating system is supported for SELECT exercises and certification. SQL handbook. English and Russian versions.
This article provides a brief SQL How-to on how to summarize data. Most of the examples we provide will be based on the ANSI-SQL 92 standard. Some examples will show features specific to SQL Server 7.
Provides ANSI-SQL solutions to common database query/update tasks. These apply to such relational databases as PostGreSQL, MySQL, Microsoft SQL Server, Oracle, Microsoft Access, SQLite.