Vol. I · A Postgres Handbook

The Query & the Schema

A reading-room reference for writing PostgreSQL by hand — selects to window functions, with the schema in plain view.

IntermediateAdvanced PostgreSQL

Theory: DDL vs DML vs DCL vs TCL

The query

SQL
-- Q: Categorize SQL commands.
-- DDL (Data Definition Language): CREATE, ALTER, DROP, TRUNCATE.
-- DML (Data Manipulation Language): SELECT, INSERT, UPDATE, DELETE.
-- DCL (Data Control Language): GRANT, REVOKE.
-- TCL (Transaction Control Language): BEGIN, COMMIT, ROLLBACK, SAVEPOINT.
Tested against PostgreSQL 16

Note

“Unlike MySQL, PostgreSQL can wrap DDL commands inside transactions. You can rollback a dropped table!