beginnerSQL Fundamentals — DDL, DML & Constraints

What is the difference between DDL and DML?

DDL (Data Definition Language) defines database structure: CREATE, ALTER, DROP, TRUNCATE. DDL statements modify the database schema (catalog) and are typically auto-committed (except in PostgreSQL which supports transactional DDL). DML (Data Manipulation Language) manipulates data within the structure: SELECT, INSERT, UPDATE, DELETE. DML operations are transactional — they can be rolled back. TRUN

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