SQL Iceberg

The article provides a comprehensive SQL cheatsheet, detailing various SQL commands and keywords essential for database management. It begins with a brief history of SQL, highlighting its evolution since its inception in 1974, particularly in response to the rise of NoSQL databases and the growing demands for analytics and cloud computing. The cheatsheet is designed for both beginners and those with some familiarity with SQL, featuring examples primarily based on Microsoft SQL Server, though applicable to other databases like PostgreSQL, MySQL, and Oracle. Key topics covered include data retrieval using SELECT statements, various types of joins (INNER, LEFT, RIGHT), the use of views, and set operations (UNION, INTERSECT, EXCEPT). The article also explains advanced concepts such as subqueries, self joins, cross joins, and the PIVOT function, which transforms rows into columns for better data visualization. Additionally, it discusses grouping techniques like ROLLUP, CUBE, and GROUPING SETS for analyzing data in subgroups. The article concludes with practical examples and SQL scripts to illustrate the discussed concepts, making it a valuable resource for anyone looking to enhance their SQL skills.

- SQL has evolved significantly since its creation in 1974, adapting to new data management needs.

- The cheatsheet covers essential SQL commands, suitable for both beginners and experienced users.

- Key SQL concepts include various types of joins, views, and set operations.

- Advanced techniques like PIVOT and grouping functions are explained for data analysis.

- Practical examples and scripts are provided to facilitate understanding and application of SQL commands.