Foundations

SQL · Beginner - the basics, step by step

• The relational model: tables, rows, columnsDiscover how a database organizes information into tables, and create your first table in SQLite.
• SELECT and WHERE: reading and filtering dataLearn to choose columns with SELECT, filter rows with WHERE and search for patterns with LIKE.
• Sorting and deduplicating: ORDER BY, LIMIT, DISTINCTMaster sorting results with ORDER BY, limiting the number of rows with LIMIT and removing duplicates with DISTINCT.
• Aggregating: COUNT, SUM, AVG, MIN/MAX and GROUP BYCompute totals, averages and per-group statistics using aggregate functions and GROUP BY.
• Modifying data: INSERT, UPDATE, DELETEAdd, modify and delete rows safely, avoiding the classic trap of the forgotten WHERE.