Tables ➔ Rows ➔ Columns ➔ Primary Keys ➔ Foreign Keys ➔ SELECT Basics ➔ FROM ➔ WHERE ➔ LIMIT / OFFSET

INSERT ➔ UPDATE ➔ DELETE

GROUP BY ➔ COUNT / SUM / AVG / MIN / MAX ➔ HAVING

INNER JOIN ➔ LEFT/RIGHT/FULL OUTER JOIN ➔ CROSS JOIN / SELF JOIN ➔ UNION / INTERSECT / EXCEPT

CREATE TABLE ➔ ALTER TABLE ➔ DROP TABLE ➔ CREATE INDEX ➔ Views

PRIMARY KEY / UNIQUE ➔ NOT NULL / CHECK ➔ FOREIGN KEY ➔ DEFAULT Values

Subqueries ➔ CTEs (WITH) ➔ Window Functions ➔ Recursive Queries

Stored Procedures & Functions ➔ Triggers ➔ Transactions ➔ Isolation Levels & Locking ➔ Error Handling

Explain Plans & Profiling ➔ Index Strategies ➔ Partitioning & Sharding ➔ Materialized Views

Users/Roles & GRANT/REVOKE ➔ Encryption ➔ Backup & Restore ➔ Monitoring & Auditing

T-SQL / PL-pgSQL / PL/SQL ➔ NoSQL vs NewSQL ➔ JSON/XML in SQL ➔ Spatial/Geodata Types