Using Liquibase with PostgreSQL

PostgreSQL is an open-source, object-relational database system that supports a large part of the SQL standard and offers many modern features:

  • complex queries
  • foreign keys
  • triggers
  • updatable views
  • transactional integrity
  • multiversion concurrency control

For more information, see the PostgreSQL documentation page.

Supported Versions

  • 9
  • 9.5
  • 10
  • 11
  • 12
  • 13
  • 14

Note: Supported versions tested with Liquibase Test Harness.

Prerequisites

Install Drivers

To use Liquibase and PostgreSQL, you need to have the JDBC driver JAR file.

Liquibase comes with a pre-installed driver for this database in the liquibase/internal/lib directory. For more information, see Adding and Updating Liquibase Drivers.

If you use Maven, you also need to download the driver JAR file and configure your Maven pom.xml file to use the local copy of the driver. For more information, see Configuring Liquibase Attributes in your Maven POM File. For example:

<dependency>
    <groupId>org.postgresql</groupId>
    <artifactId>postgresql</artifactId>
    <version>42.3.4</version>
</dependency>

Also, you can use the Liquibase PostgreSQL Extension jar file, which is the vacuum extension that adds an additional changelog tag or command to support vacuuming.

Test Your Connection

For Liquibase and PostgreSQL to work, you need to:

  1. Ensure PostgreSQL is configured. See the following:
  1. Specify the database URL in the Liquibase properties file or as a parameter to the command in the CLI. See the following:
  1. Create a text file called changelog (.xml, .sql, .json, or .yaml) in your project directory and add a changeset.
  1. Navigate to your project folder in the CLI and run the Liquibase status command to see whether the connection is successful. You can pass arguments in the CLI or keep them in the Liquibase properties file.
  2. liquibase --username=test --password=test --changelog-file=<changelog.xml> status
  3. Inspect the SQL with the update-sql command. Then make changes to your database with the update command.
  4. liquibase --changelog-file=<changelog.xml> update-sql
    liquibase --changelog-file=<changelog.xml> update

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

PostgreSQL

  • Check the status by running the pg_isready command. For more information about the options you can specify when running the command, see the pg_isready webpage.
  • Specify the database URL in the Liquibase properties file, as follows:
  • url: jdbc:postgresql://<host>:<port>/<dbname>

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

PostgreSQL on AWS RDS

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.

You can find the connection information in the AWS Management Console:

  1. Sign in to the AWS Management Console and open the Amazon RDS console.
  2. In the upper-right corner of the console, choose the AWS Region of your DB instance.
  3. 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.

Note: To find the connection information using the AWS CLI, call the describe-db-instances command: aws rds describe-db-instances. Alternatively, you can use the Amazon RDS API DescribeDBInstances operation.

Specify the database URL in the Liquibase properties file, as follows:

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

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