Working with Liquibase

How to use liquibase effectively to manage database changes and versioning

Working with liquibase

Introduction:
Liquibase is a tool used in software development to manage and version database schemas. It allows developers to define and track changes to the database over time, ensuring that everyone working on the project is using the same database structure. Think of it as a way to keep track of changes made to a database, so developers can collaborate effectively and maintain a consistent and reliable database structure as the application evolves.

How do I set it up in springboot?

Working springboot service folder structure

Step 1: Add Liquibase Dependency

In your build.gradle file, ensure you have added the Liquibase dependency:

implementation 'org.liquibase:liquibase-core'

Along with liquibase, you will need to follow the below dependencies to get it working quickly

 implementation 'org.springframework.boot:spring-boot-starter-data-jpa'

 implementation 'org.springframework.boot:spring-boot-starter-web'

 implementation 'org.liquibase:liquibase-core'
 implementation 'mysql:mysql-connector-java:8.0.23'

 compileOnly 'org.projectlombok:lombok:1.18.30'
 annotationProcessor 'org.projectlombok:lombok:1.18.30'

Below is my effective build.gradle file

plugins {
 id 'java'
 id 'org.springframework.boot' version '3.1.5'
 id 'io.spring.dependency-management' version '1.1.3'
}

group = 'com.sp.liq.learn'
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-web'

 implementation 'org.liquibase:liquibase-core'
 implementation 'mysql:mysql-connector-java:8.0.23'

 compileOnly 'org.projectlombok:lombok:1.18.30'
 annotationProcessor 'org.projectlombok:lombok:1.18.30'

 testImplementation 'org.springframework.boot:spring-boot-starter-test'

}

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

Below is my application.yml file. If you give datasource and liquibase details in the below format, upon springboot application startup, springboot will create a liquibase bean that will be used to execute your changelog scripts against the database.

spring:
  application:
    name: SP liqubase POC
  datasource:
    url: jdbc:mysql://localhost:3306/sp_liquibase_poc?createDatabaseIfNotExist=true&useLegacyDatetimeCode=false&autoReconnect=true&useSSL=false&allowPublicKeyRetrieval=true
    username: root
    password: root
    driver-class-name: com.mysql.cj.jdbc.Driver
  liquibase:
    enabled: true
    change-log: classpath:/db/changelog/db.changelog-root.xml

Under the resources/db/changelog folder, create a master changelog file. In my case, I have named this file as `db.changelog-root.xml` . This is the file where Liquibase starts its execution. Files listed in this file using the include attribute will be executed by Liquibase one by one.

<?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: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-4.1.xsd
      http://www.liquibase.org/xml/ns/pro
      http://www.liquibase.org/xml/ns/pro/liquibase-pro-4.1.xsd">
    <include file="db/changelog/dbchanges/20231021_changes.xml"/>
</databaseChangeLog>

Now you have to create a separate change log file for each change that you want to apply to the database.

In my case, I added one table creation changes to file 20231021_changes.xml and then included this file in db.changelog-root.xml file

<?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: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-4.1.xsd
      http://www.liquibase.org/xml/ns/pro
      http://www.liquibase.org/xml/ns/pro/liquibase-pro-4.1.xsd">
    <changeSet  author="codemonk"  id="13243" >
        <createTable tableName="person">
            <column  autoIncrement="true" name="id" type="BIGINT">
                <constraints  nullable="false"  primaryKey="true"  unique="true"/>
            </column>
            <column  name="name"  type="VARCHAR(255)" />
        </createTable>
    </changeSet>

</databaseChangeLog>

Now, run your springboot application; if the schema is not there, Liquibase will create one for you. If it is already there, it will use it to run the changelog scripts. After springboot application startup, you should be able to see the table in your database.