Flyway

This brief tutorial will teach how to get up and running with the Flyway Maven Plugin. It will take you through the steps on how to configure it and how to write and execute your first few database migrations.

This tutorial should take you about 5 minutes to complete.

Prerequisites

Java 17
Maven 3.x

Creating the project

We're going to create our project using the Maven Archetype Plugin by issuing the following command:

> mvn archetype:generate -B ^
    -DarchetypeGroupId=org.apache.maven.archetypes ^
    -DarchetypeArtifactId=maven-archetype-quickstart ^
    -DarchetypeVersion=1.1 ^
    -DgroupId=foo ^
    -DartifactId=bar ^
    -Dversion=1.0-SNAPSHOT ^
    -Dpackage=foobar

We are now ready to get started. Let's jump into our project:

> cd bar

Integrating Flyway

Let's integrate Flyway and the H2 database into our new pom.xml and configure Flyway so it can successfully connect to H2:

<project xmlns="...">
    <build>
        <plugins>
            <plugin>
                <groupId>org.flywaydb</groupId>
                <artifactId>flyway-maven-plugin</artifactId>
                <version>10.0.0</version>
                <configuration>
                    <url>jdbc:h2:file:./target/foobar</url>
                    <user>sa</user>
                </configuration>
                <dependencies>
                    <dependency>
                        <groupId>com.h2database</groupId>
                        <artifactId>h2</artifactId>
                        <version>2.2.224</version>
                    </dependency>
                </dependencies>
            </plugin>
        </plugins>
    </build>
</project>

Creating the first migration

We create the migration directory src/main/resources/db/migration.

Followed by a first migration called src/main/resources/db/migration/V1__Create_person_table.sql:

create table PERSON (
    ID int not null,
    NAME varchar(100) not null
);

Migrating the database

It's now time to execute Flyway to migrate our database:

bar> mvn flyway:migrate

If all went well, you should see the following output:

[INFO] Database: jdbc:h2:file:./target/foobar (H2 1.4)
[INFO] Successfully validated 1 migration (execution time 00:00.009s)
[INFO] Creating Schema History table: "PUBLIC"."flyway_schema_history"
[INFO] Current version of schema "PUBLIC": << Empty Schema >>
[INFO] Migrating schema "PUBLIC" to version 1 - Create person table
[INFO] Successfully applied 1 migration to schema "PUBLIC" (execution time 00:00.038s)

Adding a second migration

If we now add a second migration called src/main/resources/db/migration/V2__Add_people.sql:

insert into PERSON (ID, NAME) values (1, 'Axel');
insert into PERSON (ID, NAME) values (2, 'Mr. Foo');
insert into PERSON (ID, NAME) values (3, 'Ms. Bar');

and execute it by issuing:

bar> mvn flyway:migrate

We now get:

[INFO] Database: jdbc:h2:file:./target/foobar (H2 1.4)
[INFO] Successfully validated 2 migrations (execution time 00:00.012s)
[INFO] Current version of schema "PUBLIC": 1
[INFO] Migrating schema "PUBLIC" to version 2 - Add people
[INFO] Successfully applied 1 migration to schema "PUBLIC" (execution time 00:00.018s)

Summary

In this brief tutorial we saw how to

integrate the Flyway Maven plugin into a project
configure it so it can talk to our database
write our first couple of migrations

These migrations were then successfully found and executed.