Author Archives: Stanislav_Panteleev

✅ Short Answer You apply a Liquibase migration using the update command from the CLI: This command tells Liquibase to: Connect to your database Read the changelog file Apply any changesets that haven’t been run yet 🔎 Step-by-Step Command Line … Continue reading →

✅ Short Answer Yes, Liquibase can generate a changelog from an existing database schema using the generateChangeLog command.This reverse-engineers the current database structure into a changelog file (XML, YAML, JSON, or SQL) so you can start tracking and versioning it … Continue reading →

✅ Short Answer Liquibase tracks applied changes by recording each successfully executed changeset in a special database table called DATABASECHANGELOG.Each entry includes metadata like id, author, filename, checksum, and execution timestamp. 🔎 Detailed Explanation When you run liquibase update, Liquibase: … Continue reading →

✅ Short Answer runOnChange=”true” tells Liquibase to re-run a changeset if its definition changes, even if it was already applied. By default, Liquibase only runs each changeset once, but runOnChange forces Liquibase to track changes via checksums and re-apply the … Continue reading →

✅ Short Answer Preconditions in Liquibase are conditions that must be true before a changeset or changelog is applied.If the precondition fails, Liquibase can be told to halt, warn, or continue, depending on your configuration. 🔎 Detailed Explanation A precondition … Continue reading →

✅ Short Answer The DATABASECHANGELOG table is a system table created and maintained by Liquibase.It tracks which changesets have already been executed, preventing duplicates and ensuring safe, repeatable database migrations. 🔎 Detailed Explanation Whenever Liquibase applies a changeset from your … Continue reading →

✅ Short Answer Liquibase supports the following changelog file formats: XML YAML JSON Formatted SQL 🔎 Details Format Description Common Use Case XML Most powerful and fully featured Traditional projects, fine-grained control YAML More human-readable, concise Modern teams, cleaner syntax … Continue reading →

✅ Short Answer Yes, database changes can be rolled back — but only under specific conditions: ✅ In a transaction → changes can be rolled back automatically on failure. ❌ Most schema changes (DDL) like CREATE TABLE are not transactional … Continue reading →

✅ Short Answer When a migration fails: The migration process stops immediately The failed changeset is not marked as executed Any partial changes already applied by that changeset remain in the database unless you handle rollback manually ❗ No automatic … Continue reading →

✅ Short Answer Migrations are tracked using a special table in your database where the tool records every changeset or script it has applied — so it knows what’s already been done and what’s still pending. 🔎 Liquibase Tracking Liquibase … Continue reading →