SpringBoot整合Liquibase对数据库管理和迁移
简介
Liquibase是一个用于用于跟踪、管理和应用数据库变化的开源工具,通过日志文件(changelog)的形式记录数据库的变更(changeset),然后执行日志文件中的修改,将数据库更新或回滚(rollback)到一致的状态。它的目标是提供一种数据库类型无关的解决方案,通过执行schema类型的文件来达到迁移。本文主要介绍SpringBoot与Liquibase的集成。
优点
- 支持几乎所有主流的数据库,目前支持包括 Oracle/Sql Server/DB2/MySql/Sybase/PostgreSQL等 各种数据库,这样在数据库的部署和升级环节可帮助应用系统支持多数据库;
- 支持版本控制,这样就能支持多开发者的协作维护;
- 日志文件支持多种格式,如XML, YAML, JSON, SQL等;
- 提供变化应用的回滚功能,可按时间、数量或标签(tag)回滚已应用的变化。通过这种方式,开发人员可轻易的还原数据库在任何时间点的状态;
- 支持多种运行方式,如命令行、Spring集成、Maven插件、Gradle插件等。
简单示例
这里主要介绍基于SpringBoot集成liquibase来管理数据库的变更。
POM依赖
Maven 包的依赖,主要包含mysql驱动, JDBC(这里spring-boot-starter-data-jpa包含了jdbc包,当然直接引入jdbc包也行),以及liquibase包。
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.28</version>
</dependency>
<dependency>
<groupId>com.github.wenhao</groupId>
<artifactId>jpa-spec</artifactId>
<version>3.1.0</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.liquibase</groupId>
<artifactId>liquibase-core</artifactId>
<version>4.9.1</version>
</dependency>
yml配置
SpringBoot AutoConfig默认已经包含了对liquibase的配置,在spring.liquibase配置下。
基础的配置,可以直接使用如下(主要是指定change-log的位置,默认的位置是classpath:/db/changelog/db.changelog-master.yaml):
spring:
datasource:
url: jdbc:mysql://localhost:3306/test_db_liquibase?useSSL=false&autoReconnect=true&characterEncoding=utf8
driver-class-name: com.mysql.cj.jdbc.Driver
username: root
password: bfXa4Pt2lUUScy8jakXf
liquibase:
enabled: true
# 如下配置是被spring.datasource赋值的,所以可以不配置
# url: jdbc:mysql://localhost:3306/test_db_liquibase?useSSL=false&autoReconnect=true&characterEncoding=utf8
# user: root
# password: bfXa4Pt2lUUScy8jakXf
change-log: classpath:/db/changelog/db.changelog-master.yaml
新增changelog
XML方式固然OK,不过依然推荐使用yml格式。
databaseChangeLog:
- changeSet:
id: 20220412-01
author: pdai
changes:
- createTable:
tableName: person
columns:
- column:
name: id
type: int
autoIncrement: true
constraints:
primaryKey: true
nullable: false
- column:
name: firstname
type: varchar(50)
- column:
name: lastname
type: varchar(50)
constraints:
nullable: false
- column:
name: state
type: char(2)
- changeSet:
id: 20220412-02
author: pdai
changes:
- addColumn:
tableName: person
columns:
- column:
name: username
type: varchar(8)
- changeSet:
id: 20220412-03
author: pdai
changes:
- addLookupTable:
existingTableName: person
existingColumnName: state
newTableName: state
newColumnName: id
newColumnDataType: char(2)
测试
启动springBootApplication, 我们可以看到如下的几个changeSet被依次执行
2022-04-12 20:41:20.591 INFO 8476 --- [ main] liquibase.lockservice : Successfully acquired change log lock
2022-04-12 20:41:20.737 INFO 8476 --- [ main] liquibase.changelog : Creating database history table with name: test_db_liquibase.DATABASECHANGELOG
2022-04-12 20:41:20.783 INFO 8476 --- [ main] liquibase.changelog : Reading from test_db_liquibase.DATABASECHANGELOG
Running Changeset: classpath:/db/changelog/db.changelog-master.yaml::20220412-01::pdai
2022-04-12 20:41:20.914 INFO 8476 --- [ main] liquibase.changelog : Table person created
2022-04-12 20:41:20.914 INFO 8476 --- [ main] liquibase.changelog : ChangeSet classpath:/db/changelog/db.changelog-master.yaml::20220412-01::pdai ran successfully in 53ms
Running Changeset: classpath:/db/changelog/db.changelog-master.yaml::20220412-02::pdai
2022-04-12 20:41:20.952 INFO 8476 --- [ main] liquibase.changelog : Columns username(varchar(8)) added to person
2022-04-12 20:41:20.952 INFO 8476 --- [ main] liquibase.changelog : ChangeSet classpath:/db/changelog/db.changelog-master.yaml::20220412-02::pdai ran successfully in 31ms
Running Changeset: classpath:/db/changelog/db.changelog-master.yaml::20220412-03::pdai
2022-04-12 20:41:21.351 INFO 8476 --- [ main] liquibase.changelog : Lookup table added for person.state
2022-04-12 20:41:21.351 INFO 8476 --- [ main] liquibase.changelog : ChangeSet classpath:/db/changelog/db.changelog-master.yaml::20220412-03::pdai ran successfully in 389ms
2022-04-12 20:41:21.382 INFO 8476 --- [ main] liquibase.lockservice : Successfully released change log lock
查看数据库,你会发现数据已经变更
那我们如果重新启动这个SpringBootApplication,会怎么呢?
很显然,因为databasechangelog表中已经有相关执行记录了,所以将不再执行变更
2022-04-12 20:49:01.566 INFO 9144 --- [ main] liquibase.lockservice : Successfully acquired change log lock
2022-04-12 20:49:01.761 INFO 9144 --- [ main] liquibase.changelog : Reading from test_db_liquibase.DATABASECHANGELOG
2022-04-12 20:49:01.812 INFO 9144 --- [ main] liquibase.lockservice : Successfully released change log lock
## 进一步理解
### 比较好的changelog的实践
简单而言:yml格式 + sql-file方式
执行sqlFile格式的changeSet,如下
![在这里插入图片描述](https://i-blog.csdnimg.cn/direct/857a01879d394aa2a4e920c25cc069e2.png)
执行的日志如下
```log
2022-04-12 21:00:28.198 INFO 17540 --- [ main] liquibase.lockservice : Successfully acquired change log lock
2022-04-12 21:00:28.398 INFO 17540 --- [ main] liquibase.changelog : Reading from test_db_liquibase.DATABASECHANGELOG
Running Changeset: classpath:/db/changelog/db.changelog-master.yaml::20220412-04::pdai
2022-04-12 21:00:28.516 INFO 17540 --- [ main] liquibase.changelog : SQL in file classpath:/db/changelog/db.changelog-20220412-04.sql executed
2022-04-12 21:00:28.516 INFO 17540 --- [ main] liquibase.changelog : ChangeSet classpath:/db/changelog/db.changelog-master.yaml::20220412-04::pdai ran successfully in 83ms
2022-04-12 21:00:28.532 INFO 17540 --- [ main] liquibase.lockservice : Successfully released change log lock
执行后,查看变更记录
数据表user表已经创建并插入一条数据
原文地址:https://blog.csdn.net/weixin_45653328/article/details/143595349
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