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: The supported versions are the versions that were tested with Liquibase Test Harness.
Prerequisites
Before using Liquibase with your database, ensure you have:
- Installed Liquibase.
- Created a Liquibase project folder to store all Liquibase files.
- Created a new Liquibase properties file or are using the existing
liquibase.propertiesfile included in the installation package. For more information, see Specifying Properties in a Connection Profile.
Driver Information
To use Liquibase and PostgreSQL, you need to have the JDBC driver .jar file. Liquibase comes with a pre-installed driver for PostgreSQL in the liquibase/lib directory. For more information, see Adding and Updating Liquibase Drivers.
Note: If you place the postgresql-version.jar file in a different directory, specify the path in the Liquibase properties file, as follows: classpath:../path_to_drivers/postgresql-version.jar. For more information, see Specifying Properties in a Connection Profile.
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.
Testing Your Connection
For Liquibase and PostgreSQL to work, you need to:
- Ensure PostgreSQL is configured. See the following:
- Specify the database URL in the Liquibase properties file or as a parameter to the command in the CLI. See the following:
- Create a text file called changelog (
.xml,.sql,.json, or.yaml) in your project directory and add a changeset.
XML example
<?xml version="1.0" encoding="UTF-8"?>
<databaseChangeLog
xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:ext="http://www.liquibase.org/xml/ns/dbchangelog-ext"
xmlns:pro="http://www.liquibase.org/xml/ns/pro"
xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog
http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-4.9.xsd
http://www.liquibase.org/xml/ns/dbchangelog-ext http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-ext.xsd
http://www.liquibase.org/xml/ns/pro http://www.liquibase.org/xml/ns/pro/liquibase-pro-4.9.xsd">
<changeSet id="1" author="Liquibase">
<createTable tableName="test_table">
<column name="test_id" type="int">
<constraints primaryKey="true"/>
</column>
<column name="test_column" type="varchar"/>
</createTable>
</changeSet>
</databaseChangeLog>-- liquibase formatted sql
-- changeset liquibase:1
CREATE TABLE test_table (test_id INT, test_column VARCHAR, PRIMARY KEY (test_id))Note: Formatted SQL changelogs generated by using Liquibase versions previous to 4.2 might cause issues because of the lack of space after a double dash ( -- ).
Tip: To fix those issues, add a space after the double dash. For example: -- liquibase formatted sql instead of --liquibase formatted sql and -- changeset myname:create-table instead of --changeset myname:create-table
YAML example
databaseChangeLog:
- changeSet:
id: 1
author: Liquibase
changes:
- createTable:
columns:
- column:
name: test_column
type: INT
constraints:
primaryKey: true
nullable: false
tableName: test_table{
"databaseChangeLog": [
{
"changeSet": {
"id": "1",
"author": "Liquibase",
"changes": [
{
"createTable": {
"columns": [
{
"column":
{
"name": "test_column",
"type": "INT",
"constraints":
{
"primaryKey": true,
"nullable": false
}
}
}]
,
"tableName": "test_table"
}
}]
}
}]
}- 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.
- Run your first update with the update command, which makes changes to your database. You can also run the update-sql command to inspect the SQL before running the
updatecommand.
liquibase --username=test --password=test --changelog-file=<changelog.xml> statusliquibase --changelog-file=<changelog.xml> update-sql
liquibase --changelog-file=<changelog.xml> updateFrom 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_isreadycommand. 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:
- Sign in to the AWS Management Console and open 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.
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=passwordExample: url: jdbc:postgresql://myinstance.123456789012.us-east-1.rds.amazonaws.com:5432/postgresql?user=user&password=password
Supported Change Types
Supported Commands