flyway整合使用文档

参考https://blog.csdn.net/qq_34845394/article/details/90025456

​ https://stackoverflow.com/questions/64173564/failed-to-ugrade-a-spring-boot-app-to-flyway-7-0-0

由于flyway高于6.5.7的版本与 Spring Boot 2.3.4 不兼容，我们使用6.5.7这个版本

引入maven坐标

		
            org.flywaydb
            flyway-core
            6.5.7
        

# 数据源配置,注意对齐
spring:
    flyway:
        # 是否启用flyway
        enabled: true
        # 迁移sql脚本文件存放路径,默认classpath:db/migration
        # locations: classpath:db/migration
        # 当迁移发现数据库非空且存在没有元数据的表时，自动执行基准迁移，新建schema_version表
        baseline-on-migrate: true

sql脚本名称约定格式：V + 版本号 + 双下划线(__) + 描述 + 结束符(.sql)

主要是通过对比flyway_schema_history表中 version 与 checksum.来判断文件是否存在与被修改过.来执行版本控制的.

常见错误一：

sql脚本有错误，执行失败修改后重新执行报错：

nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'flywayInitializer' defined in class path resource [org/springframework/boot/autoconfigure/flyway/FlywayAutoConfiguration$FlywayConfiguration.class]: Invocation of init method failed; nested exception is org.flywaydb.core.api.FlywayException: Validate failed: 
Detected failed migration to version 20220207.3 (test delete)

需要手动修复，找到对应的约束进行删除:

DELETE FROM SPDCLOUD."flyway_schema_history" WHERe "installed_rank"=xxx;

常见错误二：

已经执行过的脚本被改动，导致校验失败

nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'flywayInitializer' defined in class path resource [org/springframework/boot/autoconfigure/flyway/FlywayAutoConfiguration$FlywayConfiguration.class]: Invocation of init method failed; nested exception is org.flywaydb.core.api.FlywayException: Validate failed: 
Migration checksum mismatch for migration version 20220207.1
-> Applied to database : -335589342
-> Resolved locally    : -725714856

还原该脚本可以解决

注意

1.特别要注意脚本文件的正确性,一定要保证脚本的正确,否则脚本执行到一半发生错误就需要手动修复(常见错误一)

2.脚本文件如果已经执行过,便不要在进行任何更改(否则无法通过校验，常见错误二)

3.如果使用了flyway进行版本管理,就不要单独执行任何sql，以保证flyway的脚本完整性