The latest version of Liquibase has a pre-installed driver for this database in the $LIQUIBASE_HOME/internal/lib directory, so you don't need to install it yourself.

If you prefer, you can use environment variables to point to the directory where Liquibase is installed on your machine. You can set environment variables using your operating system's shell. The location of $LIQUIBASE_HOME will depend on where Liquibase was installed on your machine.

Note for Maven users: If you're running Liquibase using the Maven plugin using mvn liquibase:update, installing the extension with Maven ensures the right files are available and everything works together automatically. You can manage these extensions by adding them as dependencies in your project’s pom.xml file. Configuring Maven this way ensures that the necessary JAR files are retrieved from Maven Central during the build phase.

1. Ensure your PostgreSQL database is configured

Check the connection by using any standard SQL client application, including the psql command line utility that is part of a PostgreSQL installation, and running the following:

Linux, macOS, or Unix

psql \ --host=<DB instance endpoint> \ --port=<port> \ --username=<master username> \ --password \ --dbname=<database name>

Windows

psql ^ --host=<DB instance endpoint> ^ --port=<port> ^ --username=<master username> ^ --password ^ --dbname=<database name>

Note: If this is the first time you are connecting to your DB instance, you can try using the default database name postgres for the --dbname option.

Tip: The alternative way is to connect with pgAdmin, which is an open-source administration and development tool for PostgreSQL.

2. You can find the connection information by signing into the AWS Management Console and navigating to the Amazon RDS console.

In the upper-right corner of the console, choose the AWS Region of your DB instance. Find the host and port for your DB Instance

• Select Databases and choose the needed PostgreSQL DB instance to display the instance details.

• Select Connectivity & security. You will see all information under Endpoint & Port.

3. Specify the database URL in the liquibase.properties file (defaults file), along with other properties you want to set a default value for. Liquibase does not parse the URL. You can either specify the full database connection string or specify the URL using your database's standard connection format:

url: jdbc:postgresql://<instance_host>:<instance_port>/<database_name>?user=userName&password=password

Example: url: jdbc:postgresql://myinstance.123456789012.us-east-1.rds.amazonaws.com:5432/postgresql?user=user&password=password

Tip: To apply a Liquibase Pro key to your project, add the following property to the Liquibase properties file: licenseKey: <paste code here>

1. Create a text file called changelog (.sql, .yaml, .json, or .xml) in your project directory and add a changeset.

If you already created a changelog using the init project command, you can use that instead of creating a new file. When adding onto an existing changelog, be sure to only add the changeset and to not duplicate the changelog header.

2. Navigate to your project folder in the CLI and run the Liquibase status command to see whether the connection is successful:

liquibase status --username=test --password=test --changelog-file=<changelog.xml>

Note: You can specify arguments in the CLI or keep them in the Liquibase properties file.

If your connection is successful, you'll see a message like this:

4 changesets have not been applied to <your_connection_url> Liquibase command 'status' was executed successfully.

3. Inspect the deployment SQL with the update-sql command

liquibase update-sql --changelog-file=<changelog.xml>

If the SQL that Liquibase generates isn't what you expect, you should review your changelog file and make any necessary adjustments.

4. Then execute these changes to your database with the update command:

liquibase update --changelog-file=<changelog.xml>

If your update is successful, Liquibase runs each changeset and displays a summary message ending with:

Liquibase: Update has been successful. Liquibase command 'update' was executed successfully.

5. From a database UI tool, ensure that your database contains the test_table object you added along with the DATABASECHANGELOG table and DATABASECHANGELOGLOCK table.