Spring Boot Flyway

In the same way, we find benefits in using version of control in software development with Git; we can version our database to manage changes in schema and information. Let’s go over Flyway, an open source project that help us to implement database migrations easily; that’s it, how cool would it be to see our database evolution across our development life cycle? In this example, we wil be using Gradle and Spring Boot. Let’s start creating a new Spring Boot project with web and JPA dependencies:

spring init --dependencies=webflux,mysql,jpa --build=gradle --type=gradle-project --language=java spring-boot-flyway

This is the build.gradle file generated:

plugins {
	id 'java'
	id 'org.springframework.boot' version '3.1.2'
	id 'io.spring.dependency-management' version '1.1.2'
}

group = 'com.example'
version = '0.0.1-SNAPSHOT'

java {
	sourceCompatibility = '17'
}

repositories {
	mavenCentral()
}

dependencies {
	implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
	implementation 'org.springframework.boot:spring-boot-starter-webflux'
	runtimeOnly 'com.mysql:mysql-connector-j'
	testImplementation 'org.springframework.boot:spring-boot-starter-test'
	testImplementation 'io.projectreactor:reactor-test'
}

tasks.named('test') {
	useJUnitPlatform()
}

Then let’s add Flyway plugin to the build.gradle file to connect to MySQL database:

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath("org.flywaydb:flyway-mysql:9.21.1")
    }
}

plugins {
    id 'java'
    id 'org.springframework.boot' version '3.1.2'
    id 'io.spring.dependency-management' version '1.1.2'
    id 'org.flywaydb.flyway' version '9.21.1'
}

flyway {
  url = 'jdbc:mysql://localhost:3306/flyway_demo'
}

Now let’s create first migration called src/main/resources/db/migration/V1__person_create.sql:

DROP TABLE IF EXISTS `person`;
CREATE TABLE `person` (
  `id` int NOT NULL AUTO_INCREMENT,
  `first_name` varchar(255) NOT NULL,
  `last_name` varchar(255) NOT NULL,
  PRIMARY KEY (`id`)
);

Secondly, let’s add a second migration called src/main/resources/db/migration/V2__person_insert.sql:

INSERT INTO `person` VALUES (1, 'Jose', 'Morales'), (2, 'Eric', 'Haddad')

Let’s run Flyway to migrate our database using gradle:

gradle flywayMigrate -i

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

Database: jdbc:mysql://localhost:3306/flyway_demo (MySQL 8.0)
Successfully validated 2 migrations (execution time 00:00.006s)
Creating Schema History table `flyway_demo`.`flyway_schema_history` ...
Current version of schema `flyway_demo`: << Empty Schema >>
Migrating schema `flyway_demo` to version "1 - person create"
DB: Unknown table 'flyway_demo.person' (SQL State: 42S02 - Error Code: 1051)
Migrating schema `flyway_demo` to version "2 - person insert"
Successfully applied 2 migrations to schema `flyway_demo`, now at version v2 (execution time 00:00.085s)
:flywayMigrate (Thread[Execution worker Thread 2,5,main]) completed. Took 0.865 secs.

BUILD SUCCESSFUL

We can do flywayMigrate task as dependent to bootRun task on Gradle as follow:

bootRun.dependsOn("flywayMigrate")

Here is our Person entity:

package com.jos.dem.springboot.flyway.model;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

import static javax.persistence.GenerationType.AUTO;

@Entity
public class Person {

  @Id
  @GeneratedValue(strategy = AUTO)
  Long id;

  @Column(nullable = false)
  String firstName;

  @Column(nullable = false)
  String lastName;
}

To run the project:

gradle bootRun -Dflyway.user=${username} -Dflyway.password=${pawword}

where:

• ${username} is the database username
• ${password} is the database password

To browse the project go here, to download the project:

git clone https://github.com/josdem/spring-boot-flyway.git

Return to the main article