Databases · Junior · Question 35 of 75

What is the difference between DDL and DML?

1DDL is for PostgreSQL, DML is for MySQL
2DDL is read-only, DML is write-only
✓Correct answer: DDL defines structure (CREATE, ALTER, DROP); DML works with data (SELECT, INSERT, UPDATE, DELETE)

Explanation

In PostgreSQL even DDL runs inside transactions, so a failed migration can be rolled back as a whole.

Further reading

PostgreSQL: Tutorial - The SQL language ↗

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