使用mvn liquibase:diff生成Spring Boot实体迁移时changeSets为0的问题

执行mvn liquibase:diff命令尝试从Spring Boot实体生成数据库迁移变更日志，但生成的文件为空，控制台输出：

changeSets count: 0
[INFO] No changesets to add.

相关配置与代码 #

pom.xml #

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>ch.Liquibase</groupId>
<artifactId>Liquibase</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>Liquibase</name>
<description>Liquibase</description>

<properties>
    <java.version>21</java.version>
    <spring-cloud.version>2023.0.0</spring-cloud.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.18.30</version>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
        <version>3.2.0</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <version>3.2.4</version>
    </dependency>

    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.30</version>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.liquibase</groupId>
        <artifactId>liquibase-core</artifactId>
        <version>4.24.0</version>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.11.0</version>
            <configuration>
                <source>8</source>
                <target>8</target>
            </configuration>
        </plugin>
        <plugin>
            <groupId>org.liquibase</groupId>
            <artifactId>liquibase-maven-plugin</artifactId>
            <version>4.24.0</version>
            <configuration>
                <propertyFile>src/main/resources/liquibase/config/liquibase-development.properties</propertyFile>
                <promptOnNonLocalDatabase>true</promptOnNonLocalDatabase>
            </configuration>

        </plugin>

    </plugins>
 </build>
</project>

liquibase-development.properties #

changeLogFile=src/main/resources/liquibase/liquibase-changeLog.xml
diffChangeLogFile=src/main/resources/liquibase/liquibase-diff-changeLog.xml
outputChangeLogFile=src/main/resources/liquibase/liquibase-new-changeLog.xml
url=jdbc:mysql://localhost:3306/liquibase_demo_db
defaultSchemaName=liquibase_demo_db
username=root
password=123456

driver=com.mysql.cj.jdbc.Driver

referenceDefaultSchemaName=liquibase_demo_ref
referenceDriver=com.mysql.cj.jdbc.Driver

referenceUrl=jdbc:mysql://localhost:3306/liquibase_demo_ref
referenceUsername=root
referencePassword=123456
liquibase.generateChangesetCreatedValues=true
liquibase.pro.sql.inline=true
liquibase.includeCatalogInSpecification=true
liquibase.command.diffChangeLog.format=xml
liquibase.command.diffChangeLog.skipDatabaseStep=true

application.properties #

## Database Properties
# Spring DATASOURCE (DataSourceAutoConfiguration & DataSourceProperties)
spring.datasource.url = jdbc:mysql://localhost:3306/liquibase_demo_db?useSSL=false
spring.datasource.username = root
spring.datasource.password = 123456

# Hibernate Properties
spring.jpa.database-platform = org.hibernate.dialect.MySQL8Dialect

# LIQUIBASE (LiquibaseProperties)
spring.liquibase.change-log=classpath:liquibase/liquibase-changeLog.xml
spring.datasource.initialization-mode=always
spring.liquibase.default-schema=my_schema
spring.jpa.properties.hibernate.default_schema=my_schema
spring.liquibase.enabled=true

实体类 Customer.java #

package com.example.demo.model;

import jakarta.persistence.*;
import lombok.Getter;
import lombok.Setter;

@Getter
@Setter
@Entity(name = "customers")
public class Customer {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "id", nullable = false)
    private Long id;

    private String name;
    private String surname;
    private String address;
}

启动类 DemoApplication.java #

package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class DemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}

排查与解决方案 #

1. 修正Liquibase Diff的参考源逻辑 #

liquibase:diff默认是对比两个数据库的差异，当前配置用referenceUrl指向了另一个数据库liquibase_demo_ref，如果该库和目标库结构一致，自然不会生成变更集。要从JPA实体生成变更集，需要将Hibernate元数据作为参考源：

• 修改liquibase-development.properties，替换原有reference配置：

  # 移除原reference相关配置，添加以下内容
  referenceDriver=liquibase.ext.hibernate.database.connection.HibernateDriver
  referenceUrl=hibernate:spring:com.example.demo.model?dialect=org.hibernate.dialect.MySQL8Dialect
  

• 在pom.xml中添加Liquibase Hibernate6扩展依赖（版本和liquibase-core一致）：

  <dependency>
      <groupId>org.liquibase.ext</groupId>
      <artifactId>liquibase-hibernate6</artifactId>
      <version>4.24.0</version>
  </dependency>
  

2. 统一Schema配置 #

application.properties中配置的默认schema是my_schema，但Liquibase配置文件中是liquibase_demo_db，两者不一致会导致对比失败：

• 将两处配置统一为同一个schema，比如修改application.properties：

  spring.liquibase.default-schema=liquibase_demo_db
  spring.jpa.properties.hibernate.default_schema=liquibase_demo_db
  

• 确保目标数据库中存在该schema（MySQL中需先手动创建）。

3. 修正Java版本与编译配置 #

pom.xml中java.version=21，但maven-compiler-plugin配置为source/target=8，版本不匹配会影响Liquibase读取Hibernate元数据：

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.11.0</version>
    <configuration>
        <source>21</source>
        <target>21</target>
        <release>21</release>
    </configuration>
</plugin>

4. 执行前的准备步骤 #

• 确保目标数据库liquibase_demo_db中不存在customers表（若之前Hibernate自动建表，需手动删除）；
• 先执行mvn compile编译实体类，保证Liquibase能读取到编译后的class文件；
• 再执行mvn liquibase:diff生成变更集。

内容的提问来源于stack exchange，提问作者Shafiqul Islam