Getting Started with Liquibase and YAML on Linux and macOS

After you install Liquibase, get started with our tutorial and learn how Liquibase works.

With Liquibase, SQL statements [1] are declared as Liquibase changesets [2] in a changelog file [3].

Liquibase [4] then uses the changelog to apply the changesets to target databases [5].

In this tutorial, you will use an example changelog to apply two rounds of updates to an H2 database that is included with the Liquibase installation files.

Applying updates to the database

  1. Copy the Liquibase /examples directory from the installation directory to another location on your machine.
  2. From a command line terminal, enter <your path>/examples/start-h2 to start the example H2 database. The database console opens automatically in a browser on port 9090.
  3. Open a new command line terminal and enter the following command:
  4. cd <your path>/examples/yaml
    liquibase update

    Note: When prompted about the operation's report in Liquibase Hub, enter S to skip for now.

    Liquibase applies the following updates, which are specified as Liquibase changesets in example-changelog.yaml.

    - changeSet:
           id:  1
           author:  your.name
           changes:
            - createTable:
                 tableName:  person 
                 columns:
                   - column:
                       name:  id
                       type:  int
                       autoIncrement:  true
                       constraints:
                         primaryKey:  true
                         nullable:  false
                   - column:
                       name:  name
                       type:  varchar(50)
    - changeSet:  
           id:  2
           author:  your.name
           changes:
            - createTable:
                 tableName:  company
                 columns:
                   - column:
                       name:  id
                       type:  int
                       autoIncrement:  true
                       constraints:
                         primaryKey:  true
                         nullable:  false
                   - column:
                       name:  name
                       type:  varchar(50)
    - changeSet:
           id:  3
           author:  your.name
           changes:
            - addColumn:
                 tableName:  company
                 columns:
                   - column:
                       name:  country
                       type:  varchar(2)

    The author-id value pairs your.name:1 and your.name:2 prevent their respective changesets from accidentally being run multiple times as new changesets are added to the changelog for subsequent updates.

  1. From the database console, confirm that the Object view contains the COMPANY and PERSON tables that were created during the previous step.
  1. Using a text editor, open <your path>/examples/yaml/example-changelog.yaml and add the following changesets to the end of the file:
  2. Note: When you copy the changeset, put the - changeset attribute at the beginning of a new line without any indentation.

    - changeSet:  
           id:  4
           author:  your.name
           changes:
            - addColumn:
                 tableName:  person
                 columns:
                   - column:
                       name:  country
                       type:  varchar(2)
  1. Save and close example-changelog.yaml.
  1. Enter the following command:
  2. liquibase update
  1. Confirm the update by refreshing the database console and verifying that the country column has been added to the PERSON table.

Next steps