Spring Boot Flyway

In the same way we find benefits using version of control in software development with Git, we can versioning our database so that we can manage changes in both schema and information. Let me introduce Flyway an open source project that help us to do database migrations easily, that’s it, how cool would be to see our database evolution across all 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=web,mysql,jpa --language=java --build=gradle --type=gradle-project spring-boot-flyway

This is the build.gradle file generated:

plugins {
    id 'java'
    id 'org.springframework.boot' version '2.7.7'
    id 'io.spring.dependency-management' version '1.1.0'
}

group = 'com.jos.dem.springboot.flyway'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = '17'

repositories {
    mavenCentral()
}

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
    implementation 'org.springframework.boot:spring-boot-starter-web'
    runtimeOnly 'mysql:mysql-connector-java'
    testImplementation 'org.springframework.boot:spring-boot-starter-test'
}

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

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

buildscript {
    dependencies {
        classpath 'org.flywaydb:flyway-mysql:9.8.1'
    }
}

plugins {
    id 'java'
    id 'org.springframework.boot' version '2.7.7'
    id "org.flywaydb.flyway" version "9.8.1"
    id 'io.spring.dependency-management' version '1.1.0'
}

flyway {
  url = 'jdbc:mysql://localhost:3306/flyway_demo'
  user = 'databaseUser'
  password = 'databasePassword'
}

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 in gradle as follow:

bootRun.dependsOn rootProject.tasks['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 browse the project go here, to download the project:

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

To run the project:

gradle bootRun

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