Mastering SQL: Window Functions, JOINs, CTEs, and Subqueries

SQL is a fundamental tool for data analysis, enabling the retrieval and organization of relational database information. While basic commands like SELECT and GROUP BY provide foundations, complex analysis requires JOINs, Common Table Expressions (CTEs), and subqueries. SQL Window Functions perform calculations returning one output row per input row. Key examples include ROW_NUMBER(), which assigns unique sequential numbers, and RANK(), which ranks rows based on specified orders, allowing users to calculate running totals or rank data.