Core SQL knowledge based on ANSI SQL standard. Covers DML (SELECT, INSERT,
UPDATE, DELETE), DDL (CREATE, ALTER, DROP), joins, transactions, and
fundamental database concepts. Foundation for all SQL database work.
USE WHEN: user mentions "SQL basics", "SELECT", "JOIN", "INSERT", "UPDATE", "DELETE",
"DDL", "DML", "transactions", "foreign keys", "indexes", asks about basic SQL queries
DO NOT USE FOR: reviewing existing SQL - use `review/sql`, which covers the
NULL, concurrency and plan defects nothing in the pipeline checks
DO NOT USE FOR: advanced queries (CTEs, window functions) - use `sql-advanced` instead,
PostgreSQL specifics - use `postgresql` instead, NoSQL - use `m…
