一、背景

• 我的springboot版本为2.7.5
• Flyway是一个款数据库版本管理工具，它可以很方便的在命令行中使用，或者在Java应用程序中引入，用于管理我们的数据库版本。
• 通过集成Flyway可以实现启动项目时自动执行项目迭代升级所需Sql语句,从而减少升级项目时人工干预成本。
• Flyway最核心的就是用于记录所有版本演化和状态的MetaData表，Flyway首次启动会创建默认名为SCHEMA_VERSION的元素局表。 表中保存了版本，描述，要执行的sql脚本等。

MetaData表就是元数据表，就是flyway_schema_history

• 在项目或产品中，很难一开始就把业务理清楚，把数据库表设计好，因此数据表也会在迭代周期不断迭代。在Java应用程序中使用Flyway，能快速有效地用于迭代数据库表结构，并保证部署到测试环境或生产环境时，数据表都是保持一致的。

flyway官方文档：https://flywaydb.org/documentation/

二、为什么要使用flyway

在多人开发的项目中，我们都习惯了使用SVN或者Git来对代码做版本控制，主要的目的就是为了解决多人开发代码冲突和版本回退的问题。

其实，数据库的变更也需要版本控制，在日常开发中，我们经常会遇到下面的问题：
1. 自己写的SQL忘了在所有环境执行。
2. 别人写的SQL我们不能确定是否都在所有环境执行过了。
3. 有人修改了已经执行过的SQL，期望再次执行。
4. 需要新增环境做数据迁移。
5. 每次发版需要手动控制先发DB版本，再发布应用版本。
6. 其它场景。

有了flyway，这些问题都能得到很好的解决。

三、flyway工作流程

flyway工作流程如下：

1. 项目启动，应用程序完成数据库连接池的建立后，Flyway自动运行。
2. 初次使用时，flyway会创建一个 flyway_schema_history 表，用于记录sql执行记录。
3. Flyway会扫描项目指定路径下(默认是 classpath:db/migration )的所有sql脚本，与 flyway_schema_history 表脚本记录进行比对。如果数据库记录执行过的脚本记录，与项目中的sql脚本不一致，Flyway会报错并停止项目执行。
4. 如果校验通过，则根据表中的sql记录最大版本号，忽略所有版本号不大于该版本的脚本。再按照版本号从小到大，逐个执行其余脚本。

四、文件命名规范

格式: V + 版本号 + __ (双下划线) + 描述.sql

• Eg:
  • 版本升级: V1_2_0__upgrade.sql（不推荐，因为小版本改动“1_2_0”这个数值不好一直叠加）
  • BUG修复: V1_2_0_20220816__hotfix.sql
  • V20221104_10001.sql（推荐这种命名方式，其中20221102代表日期，10001代表SVN或者Git的提交版本号，便于迭代）
  • V20221104_10001__add.sql（也推荐使用这种，双下划线后面加点描述词）
• 规则说明:
  • 前缀分隔符
    • V: 版本化迁移 (使用)
      • 默认V开头 (可配置)
      • V(大些),小些不执行
    • R: 可重复迁移 (不使用)
      • 新增或追加脚本时再次执行该文件所有脚本(包括历史sql)
      • 历史sql脚本不可更改
      • 不需要指定脚步版本
    • U: 撤销迁移 (不使用)
      • 编写各版本对应撤销版本脚步
      • 需要通过Flyway客户端执行撤销命令,执行最近一次版本撤销
      • 撤销场景较复杂,建议版本升级前进行DB备份,实现撤销
  • SQL脚本版本
    • 2_1为sql版本号, ‘_’ 翻译为小数点,即为2.1版本
    • 新建脚本,版本只可递增
    • 不可使用V1作为版本号
  • 分隔符
    • ‘__’ 双下划线 (可配置)
  • SQL脚本名描述(待定)
    • 多个单词用下划线或空格将单词分开
    • 版本化升级: upgrade
    • BUG修复: hotfix
  • .sql为固定后缀

五、Flyway 的迁移类型

版本迁移：以V开头的文件

最常见的迁移就是就是版本化迁移，每次迁移都会对应的迁移版本，迁移的版本必须全局唯一，版本迁移最大的特点就是依次只被执行依次。

撤销迁移：以U开头的文件（这个U开头的撤销文件我没玩明白如何使用，后续研究明白了再补上）

每个撤销迁移都对应的一个版本迁移，也就是说撤销迁移是针对版本迁移所存在的，每一个撤销迁移与版本迁移都是一一对应的，而且对应的版本号必须一致。

可重复迁移:以R开头的文件

可重复迁移有描述和校验码，但是没有版本号，程序在每次启动的时候，如果发现脚本文件有变化就会执行。

基于 SQL 的迁移

上面提到的几种类型都是基于 SQL 文件来执行的，只不过每种类型的命名格式不一样，下图是从官网上截下来的，大家看下每种类型的文件应该按照如下的格式去命令，其中的 Separator 是两个下划线。

主要分为下面几个部分：

prefix：前缀，不同的类型采用不同的前缀，版本迁移使用 V，撤销迁移使用 U，可重复迁移使用 R，当然这些都是可配置的；

Version：版本号，可以使用点符号或者单下划线链接；

Separator：分隔符，两个下划线，也是可以配置的；

Description：版本描述可以用下划线和空格分隔；

Suffix：后缀，一般都是 .sql

六、sql迁移文件执行的迁移流程

1）Flyway 会扫描配置的脚本目录下的脚本文件；
2）如果历史记录表不存在，则新建历史记录表；
3）如果是一次性执行脚本（V），按版本号从小到大执行迁移脚本，与当前历史表中的版本号做对比，大于当前版本号的脚本才会被执行迁移；
4）如果是可重复执行脚本（R），检查脚本是否有变动，有变动的可重复脚本才会被执行迁移；

七、注意事项

1. Fayway在每次应用启动时检测是否有需要执行的升级脚本；

2. 文件名以V作为前缀的，后跟版本号，版本号格式可以为为大版本号（1、2），也可以包含小版本号(1.1或1_1)，但是需统一，不能有些有小版本号，有些没有；

3. 前缀为V的脚本不可重复执行，每个脚本只会被执行一次。已经执行过的历史版本脚本不能再修改，除非清除flayway的历史记录，重新执行升级脚本，这在生产环境不允许。

前缀为R的脚本，后面无版本号，如R__update_version.sql，可以重复执行，每次内容发生变化时重启后就会执行。

4. Flyway需要创建存储脚本升级记录用的表，因此需要建表权限，也可以事先建好。默认表名为flyway_schema_history；

八、SpringBoot 项目使用 Flyway步骤

项目目录

第1步：引入pom

第1步：引入pom

<dependencies>
    <!--解决@RestController注解爆红-->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <version>${spring.boot.starter.web.version}</version>
    </dependency>

    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>${lombok.version}</version>
    </dependency>

    <!--使用flyway-->
    <dependency>
        <groupId>org.flywaydb</groupId>
        <artifactId>flyway-core</artifactId>
        <version>${flayway.test.version}</version>
    </dependency>

    <!--mysql相关-->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
        <version>${mysql.connector.java.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
        <version>${spring.boot.starter.jdbc.version}</version>
    </dependency>

    <!--
        必须配置相关slf4j的依赖，否则启动报错：说缺少日志框架的相关实现。
        注意：必须设置1.7.x及之前的版本，如果输入2.0.x版本会报错：SLF4J: Class path contains SLF4J bindings targeting slf4j-api versions 1.7.x or earlier
    -->
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-api</artifactId>
       <version>${slf4j.api.version}</version>
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-log4j12</artifactId>
        <version>${slf4j.log4j12.version}</version>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.flywaydb</groupId>
            <artifactId>flyway-maven-plugin</artifactId>
            <version>${flayway.test.version}</version>
            <configuration>
                <user>root</user>
                <password>123456</password>
                <driver>com.mysql.jdbc.Driver</driver>
                <url>jdbc:mysql://10.110.13.86:3306/flyway?characterEncoding=utf8</url>
                <baselineOnMigrate>true</baselineOnMigrate>
                <!--sql脚本位置，flyway会自动去找到这个目录并且执行里面的sql脚本-->
                <locations>classpath:db/migration/</locations>
            </configuration>
        </plugin>
    </plugins>
</build>

我的项目是父模块模式，所以版本号在父pom中指定

<properties>
	<spring.boot.starter.web.version>2.6.3</spring.boot.starter.web.version>
	<lombok.version>1.18.22</lombok.version>
	<flayway.test.version>6.5.7</flayway.test.version>
	<mysql.connector.java.version>8.0.31</mysql.connector.java.version>
	<spring.boot.starter.jdbc.version>2.7.5</spring.boot.starter.jdbc.version>
	<slf4j.api.version>1.7.33</slf4j.api.version>
	<slf4j.log4j12.version>1.7.33</slf4j.log4j12.version>
</properties>

第2步：配置文件application.yml

# 端口号
server:
  port: 8015

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://10.110.13.86:3306/flyway?characterEncoding=utf8
    username: root
    password: 123456
    hikari:
      minimum-idle: 5 #最小空闲连接数
      idle-timeout: 180000 #空闲连接存活最大时间，默认600000
      maximum-pool-size: 10 #连接池最大连接数
      auto-commit: true #自动提交 默认true
      pool-name: HikariCP #连接池名称
      max-lifetime: 1800000 #连接池最长生命周期，0表示无限生命周期，默认1800000(30分钟)
      connection-timeout: 30000 #连接超时时间，默认30000
      connection-test-query: SELECT 1

  # flayway相关配置
  flyway:
    locations: classpath:db/migration   #这个路径指的是fly版本控制的sql语句存放的路径,可以多个，可以给每个环境使用不同位置,比如classpath:db/migration,classpath:test/db/migration
    baseline-on-migrate: true   #开启自动创建flyway元数据表标识 默认: false
    enabled: true   #是否启用flyway(默认true)
    clean-disabled: true    #禁止flyway执行清理
    table: flyway_schema_history  #用于记录所有的版本变化记录

第3步：编写sql迁移脚本文件

就是写了1个简单的create创建语句、以及insert添加、update修改语句

V1.0__create_flyway_test_table.sql

CREATE TABLE flyway_test_table (
   engine_name VARCHAR(64) NOT NULL COLLATE 'utf8_general_ci',
   device_type INT(11) NOT NULL,
   cost_name VARCHAR(64) NOT NULL,
   cost_value FLOAT NULL DEFAULT NULL,
   last_update TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
   comment VARCHAR(1024) NULL DEFAULT NULL,
   PRIMARY KEY (engine_name) USING BTREE
)
COLLATE='utf8_general_ci'
ENGINE=InnoDB;

V1.1__add_flyway_test_table.sql

INSERT INTO flyway_test_table (engine_name, device_type, cost_name, cost_value, last_update, comment) VALUES ('34000', 0, 'io_block_read_cost', NULL, '2022-10-21 03:32:08', NULL);
INSERT INTO flyway_test_table (engine_name, device_type, cost_name, cost_value, last_update, comment) VALUES ('34003', 0, 'io_block_read_cost', NULL, '2022-10-21 03:32:08', NULL);

V20221101__10381.sql

INSERT INTO flyway_test_table (engine_name, device_type, cost_name, cost_value, last_update, comment) VALUES ('34001', 0, 'io_block_read_cost', NULL, '2022-10-21 03:32:08', NULL);

R__10382.sql

UPDATE flyway_test_table set engine_name='34005' where engine_name = '34000';

第4步：创建启动类FlaywayApplication

package com.flyway;

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

/**
 * Spring Boot使用flayway自动执行数据库升级脚本
 * @Author 211145187
 * @Date 2022/9/20 14:33
 **/
@SpringBootApplication
public class FlaywayApplication {
    public static void main(String[] args) {
        SpringApplication.run(FlaywayApplication.class, args);
    }
}

九、项目启动后的数据库结果展示

项目启动后控制台日志打印

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::                (v2.6.3)

2022-11-01 13:34:01.873  INFO 21004 --- [           main] com.flyway.FlaywayApplication            : Starting FlaywayApplication using Java 1.8.0_71 on HYT211145187-01 with PID 21004 (G:\WorkSpace\springboot-test\flyway-test\target\classes started by 211145187 in G:\WorkSpace\springboot-test)
2022-11-01 13:34:01.876  INFO 21004 --- [           main] com.flyway.FlaywayApplication            : No active profile set, falling back to default profiles: default
2022-11-01 13:34:02.861  INFO 21004 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8015 (http)
2022-11-01 13:34:02.898  INFO 21004 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2022-11-01 13:34:02.899  INFO 21004 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.56]
2022-11-01 13:34:03.005  INFO 21004 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2022-11-01 13:34:03.005  INFO 21004 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1086 ms
2022-11-01 13:34:03.400  INFO 21004 --- [           main] o.f.c.internal.license.VersionPrinter    : Flyway Community Edition 6.5.7 by Redgate
2022-11-01 13:34:03.405  INFO 21004 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariCP - Starting...
2022-11-01 13:34:13.747  INFO 21004 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariCP - Start completed.
2022-11-01 13:34:13.766  INFO 21004 --- [           main] o.f.c.internal.database.DatabaseFactory  : Database: jdbc:mysql://10.110.13.86:3306/mysql (MySQL 5.7)
2022-11-01 13:34:13.822  INFO 21004 --- [           main] o.f.core.internal.command.DbValidate     : Successfully validated 2 migrations (execution time 00:00.029s)
2022-11-01 13:34:13.832  INFO 21004 --- [           main] o.f.core.internal.command.DbMigrate      : Current version of schema `mysql`: << Empty Schema >>
2022-11-01 13:34:13.847  INFO 21004 --- [           main] o.f.core.internal.command.DbMigrate      : Migrating schema `mysql` to version 1.0 - create flyway test table
2022-11-01 13:34:13.884  INFO 21004 --- [           main] o.f.core.internal.command.DbMigrate      : Migrating schema `mysql` to version 1.1 - add flyway test table
2022-11-01 13:34:13.901  INFO 21004 --- [           main] o.f.core.internal.command.DbMigrate      : Successfully applied 2 migrations to schema `mysql` (execution time 00:00.075s)
2022-11-01 13:34:14.004  INFO 21004 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8015 (http) with context path ''
2022-11-01 13:34:14.013  INFO 21004 --- [           main] com.flyway.FlaywayApplication            : Started FlaywayApplication in 12.628 seconds (JVM running for 13.458)

Process finished with exit code -1

flyway库下的表结构

flyway_schema_history

flyway_test_table

十、flyway拓展知识

flyway.baseline-description对执行迁移时基准版本的描述.
flyway.baseline-on-migrate当迁移时发现目标schema非空，而且带有没有元数据的表时，是否自动执行基准迁移，默认false.
flyway.baseline-version开始执行基准迁移时对现有的schema的版本打标签，默认值为1.
flyway.check-location检查迁移脚本的位置是否存在，默认false.
flyway.clean-on-validation-error当发现校验错误时是否自动调用clean，默认false.
flyway.enabled是否开启flywary，默认true.
flyway.encoding设置迁移时的编码，默认UTF-8.
flyway.ignore-failed-future-migration当读取元数据表时是否忽略错误的迁移，默认false.
flyway.init-sqls当初始化好连接时要执行的SQL.
flyway.locations迁移脚本的位置，默认db/migration.
flyway.out-of-order是否允许无序的迁移，默认false.
flyway.password目标数据库的密码.
flyway.placeholder-prefix设置每个placeholder的前缀，默认${.
flyway.placeholder-replacementplaceholders是否要被替换，默认true.
flyway.placeholder-suffix设置每个placeholder的后缀，默认}.
flyway.placeholders.[placeholder name]设置placeholder的value
flyway.schemas设定需要flywary迁移的schema，大小写敏感，默认为连接默认的schema.
flyway.sql-migration-prefix迁移文件的前缀，默认为V.
flyway.sql-migration-separator迁移脚本的文件名分隔符，默认__
flyway.sql-migration-suffix迁移脚本的后缀，默认为.sql
flyway.tableflyway使用的元数据表名，默认为schema_version
flyway.target迁移时使用的目标版本，默认为latest version
flyway.url迁移时使用的JDBC URL，如果没有指定的话，将使用配置的主数据源
flyway.user迁移数据库的用户名
flyway.validate-on-migrate迁移时是否校验，默认为true.

十一、练习使用flyway碰到的错误场景及解决方案

错误场景1：Correct the classpath of your application so that it contains compatible versions of the classes org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration$FlywayConfiguration and org.flywaydb.core.api.configuration.FluentConfiguration

详情错误日志

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::                (v2.6.3)

2022-11-01 10:52:01.616  INFO 26424 --- [           main] com.flyway.FlaywayApplication            : Starting FlaywayApplication using Java 11.0.12 on HYT211145187-01 with PID 26424 (G:\WorkSpace\springboot-test\flyway-test\target\classes started by 211145187 in G:\WorkSpace\springboot-test)
2022-11-01 10:52:01.619  INFO 26424 --- [           main] com.flyway.FlaywayApplication            : No active profile set, falling back to default profiles: default
2022-11-01 10:52:02.677  INFO 26424 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8015 (http)
2022-11-01 10:52:02.691  INFO 26424 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2022-11-01 10:52:02.691  INFO 26424 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.56]
2022-11-01 10:52:02.778  INFO 26424 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2022-11-01 10:52:02.779  INFO 26424 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1070 ms
2022-11-01 10:52:03.148  WARN 26424 --- [           main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'flyway' defined in class path resource [org/springframework/boot/autoconfigure/flyway/FlywayAutoConfiguration$FlywayConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.flywaydb.core.Flyway]: Factory method 'flyway' threw exception; nested exception is java.lang.NoSuchMethodError: org.flywaydb.core.api.configuration.FluentConfiguration.ignoreMissingMigrations(Z)Lorg/flywaydb/core/api/configuration/FluentConfiguration;
2022-11-01 10:52:03.151  INFO 26424 --- [           main] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
2022-11-01 10:52:03.161  INFO 26424 --- [           main] ConditionEvaluationReportLoggingListener : 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2022-11-01 10:52:03.177 ERROR 26424 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   : 

***************************
APPLICATION FAILED TO START
***************************

Description:

An attempt was made to call a method that does not exist. The attempt was made from the following location:

    org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration$FlywayConfiguration.configureIgnoredMigrations(FlywayAutoConfiguration.java:273)

The following method did not exist:

    org.flywaydb.core.api.configuration.FluentConfiguration.ignoreMissingMigrations(Z)Lorg/flywaydb/core/api/configuration/FluentConfiguration;

The calling method's class, org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration$FlywayConfiguration, was loaded from the following location:

    jar:file:/F:/apache-maven-3.6.3/repository/org/springframework/boot/spring-boot-autoconfigure/2.6.3/spring-boot-autoconfigure-2.6.3.jar!/org/springframework/boot/autoconfigure/flyway/FlywayAutoConfiguration$FlywayConfiguration.class

The called method's class, org.flywaydb.core.api.configuration.FluentConfiguration, is available from the following locations:

    jar:file:/F:/apache-maven-3.6.3/repository/org/flywaydb/flyway-core/9.6.0/flyway-core-9.6.0.jar!/org/flywaydb/core/api/configuration/FluentConfiguration.class

The called method's class hierarchy was loaded from the following locations:

    org.flywaydb.core.api.configuration.FluentConfiguration: file:/F:/apache-maven-3.6.3/repository/org/flywaydb/flyway-core/9.6.0/flyway-core-9.6.0.jar


Action:

Correct the classpath of your application so that it contains compatible versions of the classes org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration$FlywayConfiguration and org.flywaydb.core.api.configuration.FluentConfiguration

错误原因：pom中flyway-core的依赖版本问题，当设置9.6.0时就报这个错误，但当设置6.5.7时就能正常启动，感觉是flyway高版本和springboot2.x版本不匹配的问题导致的问题，具体为啥目前不清楚，只要把flyway版本设置成5.2.1或者6.5.7版本以及之间的版本那都是可以运行的。

错误场景2：SLF4J: No SLF4J providers were found.或者SLF4J: Defaulting to no-operation (NOP) logger implementation

详情错误日志

SLF4J: No SLF4J providers were found.
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See https://www.slf4j.org/codes.html#noProviders for further details.
SLF4J: Class path contains SLF4J bindings targeting slf4j-api versions 1.7.x or earlier.
SLF4J: Ignoring binding found at [jar:file:/F:/apache-maven-3.6.3/repository/ch/qos/logback/logback-classic/1.2.10/logback-classic-1.2.10.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See https://www.slf4j.org/codes.html#ignoredBindings for an explanation.

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::                (v2.6.3)

报错原因：pom中没有slf4j的相关框架实现，即现在项目只有框架门面，而缺少具体的框架实现。

解决方案：pom中添加如下2个依赖即可解决问题。

<dependency>
	<groupId>org.slf4j</groupId>
	<artifactId>slf4j-api</artifactId>
	<version>1.7.33</version>
</dependency>
<dependency>
	<groupId>org.slf4j</groupId>
	<artifactId>slf4j-log4j12</artifactId>
	<version>1.7.33</version>
</dependency>

可参考如下其他人博客：↓

SLF4J 报错解决：No SLF4J providers were found

错误场景3：java.sql.SQLSyntaxErrorException: Unknown database ‘flyway’

详情错误日志

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::                (v2.6.3)

2022-11-01 13:34:54.569  INFO 7488 --- [           main] com.flyway.FlaywayApplication            : Starting FlaywayApplication using Java 1.8.0_71 on HYT211145187-01 with PID 7488 (G:\WorkSpace\springboot-test\flyway-test\target\classes started by 211145187 in G:\WorkSpace\springboot-test)
2022-11-01 13:34:54.572  INFO 7488 --- [           main] com.flyway.FlaywayApplication            : No active profile set, falling back to default profiles: default
2022-11-01 13:34:55.624  INFO 7488 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8015 (http)
2022-11-01 13:34:55.634  INFO 7488 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2022-11-01 13:34:55.634  INFO 7488 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.56]
2022-11-01 13:34:55.730  INFO 7488 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2022-11-01 13:34:55.730  INFO 7488 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1111 ms
2022-11-01 13:34:56.117  INFO 7488 --- [           main] o.f.c.internal.license.VersionPrinter    : Flyway Community Edition 6.5.7 by Redgate
2022-11-01 13:34:56.122  INFO 7488 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariCP - Starting...
2022-11-01 13:35:07.441 ERROR 7488 --- [           main] com.zaxxer.hikari.pool.HikariPool        : HikariCP - Exception during pool initialization.

java.sql.SQLSyntaxErrorException: Unknown database 'flyway'
	at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:120) ~[mysql-connector-j-8.0.31.jar:8.0.31]
	at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:122) ~[mysql-connector-j-8.0.31.jar:8.0.31]
	at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:828) ~[mysql-connector-j-8.0.31.jar:8.0.31]
	at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:448) ~[mysql-connector-j-8.0.31.jar:8.0.31]
	at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:241) ~[mysql-connector-j-8.0.31.jar:8.0.31]
	at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:198) ~[mysql-connector-j-8.0.31.jar:8.0.31]
	at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:138) ~[HikariCP-4.0.3.jar:na]
	at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:364) ~[HikariCP-4.0.3.jar:na]
	at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:206) ~[HikariCP-4.0.3.jar:na]
	at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:476) [HikariCP-4.0.3.jar:na]
	at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:561) [HikariCP-4.0.3.jar:na]
	at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:115) [HikariCP-4.0.3.jar:na]
	at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) [HikariCP-4.0.3.jar:na]
	at org.flywaydb.core.internal.jdbc.JdbcUtils.openConnection(JdbcUtils.java:56) [flyway-core-6.5.7.jar:na]
	at org.flywaydb.core.internal.jdbc.JdbcConnectionFactory.<init>(JdbcConnectionFactory.java:80) [flyway-core-6.5.7.jar:na]
	at org.flywaydb.core.Flyway.execute(Flyway.java:453) [flyway-core-6.5.7.jar:na]
	at org.flywaydb.core.Flyway.migrate(Flyway.java:158) [flyway-core-6.5.7.jar:na]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_71]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_71]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_71]
	at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_71]
	at org.springframework.boot.autoconfigure.flyway.FlywayMigrationInitializer.afterPropertiesSet(FlywayMigrationInitializer.java:70) [spring-boot-autoconfigure-2.6.3.jar:2.6.3]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1863) [spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1800) [spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:620) [spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) [spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) [spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) [spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) [spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322) [spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) [spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:953) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918) ~[spring-context-5.3.15.jar:5.3.15]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.15.jar:5.3.15]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:732) ~[spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:414) ~[spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:302) ~[spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1303) ~[spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1292) ~[spring-boot-2.6.3.jar:2.6.3]
	at com.flyway.FlaywayApplication.main(FlaywayApplication.java:14) ~[classes/:na]

错误原因：mysql数据库下没有叫flyway的数据库。

解决方案：必须先创建名为flyway的数据库后，才能设置url: jdbc:mysql://10.110.13.86:3306/flyway?characterEncoding=utf8。

错误场景4：Caused by: org.flywaydb.core.api.FlywayException: Validate failed: Detected failed migration to version 1.0 (create flyway test table)

详情错误日志

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::                (v2.6.3)

2022-11-01 13:56:26.099  INFO 25648 --- [           main] com.flyway.FlaywayApplication            : Starting FlaywayApplication using Java 1.8.0_71 on HYT211145187-01 with PID 25648 (G:\WorkSpace\springboot-test\flyway-test\target\classes started by 211145187 in G:\WorkSpace\springboot-test)
2022-11-01 13:56:26.102  INFO 25648 --- [           main] com.flyway.FlaywayApplication            : No active profile set, falling back to default profiles: default
2022-11-01 13:56:27.276  INFO 25648 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8015 (http)
2022-11-01 13:56:27.312  INFO 25648 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2022-11-01 13:56:27.312  INFO 25648 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.56]
2022-11-01 13:56:27.401  INFO 25648 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2022-11-01 13:56:27.401  INFO 25648 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1249 ms
2022-11-01 13:56:27.778  INFO 25648 --- [           main] o.f.c.internal.license.VersionPrinter    : Flyway Community Edition 6.5.7 by Redgate
2022-11-01 13:56:27.784  INFO 25648 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariCP - Starting...
2022-11-01 13:56:38.112  INFO 25648 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariCP - Start completed.
2022-11-01 13:56:38.130  INFO 25648 --- [           main] o.f.c.internal.database.DatabaseFactory  : Database: jdbc:mysql://10.110.13.86:3306/flyway (MySQL 5.7)
2022-11-01 13:56:38.193  WARN 25648 --- [           main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: 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 java.lang.reflect.InvocationTargetException
2022-11-01 13:56:38.193  INFO 25648 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariCP - Shutdown initiated...
2022-11-01 13:56:38.197  INFO 25648 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariCP - Shutdown completed.
2022-11-01 13:56:38.200  INFO 25648 --- [           main] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
2022-11-01 13:56:38.209  INFO 25648 --- [           main] ConditionEvaluationReportLoggingListener : 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2022-11-01 13:56:38.238 ERROR 25648 --- [           main] o.s.boot.SpringApplication               : Application run failed

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'flywayInitializer' defined in class path resource [org/springframework/boot/autoconfigure/flyway/FlywayAutoConfiguration$FlywayConfiguration.class]: Invocation of init method failed; nested exception is java.lang.reflect.InvocationTargetException
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1804) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:620) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:953) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918) ~[spring-context-5.3.15.jar:5.3.15]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.15.jar:5.3.15]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:732) [spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:414) [spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:302) [spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1303) [spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1292) [spring-boot-2.6.3.jar:2.6.3]
	at com.flyway.FlaywayApplication.main(FlaywayApplication.java:14) [classes/:na]
Caused by: java.lang.reflect.InvocationTargetException: null
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_71]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_71]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_71]
	at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_71]
	at org.springframework.boot.autoconfigure.flyway.FlywayMigrationInitializer.afterPropertiesSet(FlywayMigrationInitializer.java:70) ~[spring-boot-autoconfigure-2.6.3.jar:2.6.3]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1863) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1800) ~[spring-beans-5.3.15.jar:5.3.15]
	... 18 common frames omitted
Caused by: org.flywaydb.core.api.FlywayException: Validate failed: 
Detected failed migration to version 1.0 (create flyway test table)

	at org.flywaydb.core.Flyway.doValidate(Flyway.java:292) ~[flyway-core-6.5.7.jar:na]
	at org.flywaydb.core.Flyway.access$100(Flyway.java:73) ~[flyway-core-6.5.7.jar:na]
	at org.flywaydb.core.Flyway$1.execute(Flyway.java:166) ~[flyway-core-6.5.7.jar:na]
	at org.flywaydb.core.Flyway$1.execute(Flyway.java:158) ~[flyway-core-6.5.7.jar:na]
	at org.flywaydb.core.Flyway.execute(Flyway.java:527) ~[flyway-core-6.5.7.jar:na]
	at org.flywaydb.core.Flyway.migrate(Flyway.java:158) ~[flyway-core-6.5.7.jar:na]
	... 25 common frames omitted

错误原因：数据库涉及的2张表没全删掉（可能有一个表还存在情况下启动的项目），如图，我这边模拟的场景是第一次启动项目，实现第一个sql创建DDL的创建表语句，第二个sql插入一条数据的场景，但是我涉及的的2个表flyway_schema_history和flyway_test_table没删掉。

解决方案：这两个表都删除情况下再重新启动项目

错误场景5：Migration checksum mismatch for migration version 1.1 -> Applied to database : 1332862643 -> Resolved locally : -826751737

详情错误日志

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::                (v2.6.3)

2022-11-01 14:50:33.363  INFO 26596 --- [           main] com.flyway.FlaywayApplication            : Starting FlaywayApplication using Java 1.8.0_71 on HYT211145187-01 with PID 26596 (G:\WorkSpace\springboot-test\flyway-test\target\classes started by 211145187 in G:\WorkSpace\springboot-test)
2022-11-01 14:50:33.366  INFO 26596 --- [           main] com.flyway.FlaywayApplication            : No active profile set, falling back to default profiles: default
2022-11-01 14:50:34.336  INFO 26596 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8015 (http)
2022-11-01 14:50:34.372  INFO 26596 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2022-11-01 14:50:34.373  INFO 26596 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.56]
2022-11-01 14:50:34.460  INFO 26596 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2022-11-01 14:50:34.460  INFO 26596 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1052 ms
2022-11-01 14:50:34.839  INFO 26596 --- [           main] o.f.c.internal.license.VersionPrinter    : Flyway Community Edition 6.5.7 by Redgate
2022-11-01 14:50:34.844  INFO 26596 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariCP - Starting...
2022-11-01 14:50:45.205  INFO 26596 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariCP - Start completed.
2022-11-01 14:50:45.225  INFO 26596 --- [           main] o.f.c.internal.database.DatabaseFactory  : Database: jdbc:mysql://10.110.13.86:3306/flyway (MySQL 5.7)
2022-11-01 14:50:45.297  WARN 26596 --- [           main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: 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 java.lang.reflect.InvocationTargetException
2022-11-01 14:50:45.297  INFO 26596 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariCP - Shutdown initiated...
2022-11-01 14:50:45.301  INFO 26596 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariCP - Shutdown completed.
2022-11-01 14:50:45.305  INFO 26596 --- [           main] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
2022-11-01 14:50:45.314  INFO 26596 --- [           main] ConditionEvaluationReportLoggingListener : 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2022-11-01 14:50:45.343 ERROR 26596 --- [           main] o.s.boot.SpringApplication               : Application run failed

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'flywayInitializer' defined in class path resource [org/springframework/boot/autoconfigure/flyway/FlywayAutoConfiguration$FlywayConfiguration.class]: Invocation of init method failed; nested exception is java.lang.reflect.InvocationTargetException
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1804) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:620) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:953) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918) ~[spring-context-5.3.15.jar:5.3.15]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.15.jar:5.3.15]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:732) [spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:414) [spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:302) [spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1303) [spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1292) [spring-boot-2.6.3.jar:2.6.3]
	at com.flyway.FlaywayApplication.main(FlaywayApplication.java:14) [classes/:na]
Caused by: java.lang.reflect.InvocationTargetException: null
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_71]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_71]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_71]
	at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_71]
	at org.springframework.boot.autoconfigure.flyway.FlywayMigrationInitializer.afterPropertiesSet(FlywayMigrationInitializer.java:70) ~[spring-boot-autoconfigure-2.6.3.jar:2.6.3]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1863) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1800) ~[spring-beans-5.3.15.jar:5.3.15]
	... 18 common frames omitted
Caused by: org.flywaydb.core.api.FlywayException: Validate failed: 
Migration checksum mismatch for migration version 1.1
-> Applied to database : 1332862643
-> Resolved locally    : -826751737

	at org.flywaydb.core.Flyway.doValidate(Flyway.java:292) ~[flyway-core-6.5.7.jar:na]
	at org.flywaydb.core.Flyway.access$100(Flyway.java:73) ~[flyway-core-6.5.7.jar:na]
	at org.flywaydb.core.Flyway$1.execute(Flyway.java:166) ~[flyway-core-6.5.7.jar:na]
	at org.flywaydb.core.Flyway$1.execute(Flyway.java:158) ~[flyway-core-6.5.7.jar:na]
	at org.flywaydb.core.Flyway.execute(Flyway.java:527) ~[flyway-core-6.5.7.jar:na]
	at org.flywaydb.core.Flyway.migrate(Flyway.java:158) ~[flyway-core-6.5.7.jar:na]
	... 25 common frames omitted


Process finished with exit code 1

报错原因：修改了已经执行过的迁移文件，比如V开头的叫V1.1__add_flyway_test_table.sql这个名字的文件，重新执行这个更改的迁移文件时就会产生新的校验和“checkSum”与原来校验和不符合，导致报该错误，原则上不可以直接修改已经执行的迁移文件，要修改需要新建迁移文件进行修改。

举例说明：比如最开始我有个文件V1.1__add_flyway_test_table.sql，里面有个insert插入一条数据的sql，然后我启动整个项目，执行sql插入一条数据，且V开头的文件按常理已经执行过一次了，后面压根不会再次执行，但我手欠儿，再次对V开头的文件V1.1__add_flyway_test_table.sql进行修改或者新增几条sql，然后再次启动项目就会报错误5的错误了。

解决方案：

• 1）方案1（不推荐）：涉及的2张表flyway_schema_history和flyway_test_table都删除，这会造成已有的数据丢失、混乱。
• 2）方案2（推荐）：可以使用Flyway Maven 插件，双击运行：flyway:repair ，修复该错误，再重新执行：flyway:migrate。这样项目就能再次启动。
• 3）方案3（不推荐）：删除2张表flyway_schema_history和flyway_test_table，然后重新启动项目把所有sql脚本从头到尾执行一遍。缺点：万一数据量太大太耗时，甚至可能出错。

碰到个问题：原来的V1.1__add_flyway_test_table.sql里面有个内容，然后我对它修改后，执行flyway:repair，在执行flyway:migrate后，再次启动项目发现V1.1__add_flyway_test_table.sql新增的内容没有执行？数据库没有产生新数据？

答案：应该是不会执行的，除非新增个V开头的迁移文件才会执行，即：对已经执行过的V开头的迁移文件修改后也不会执行，需要新建迁移文件进行修改才会生效。

错误场景6：Caused by: java.lang.NoSuchMethodError: org.flywaydb.core.api.configuration.FluentConfiguration.ignoreMissingMigrations(Z)Lorg/flywaydb/core/api/configuration/FluentConfiguration;

详情错误日志

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::                (v2.6.3)

2022-11-01 16:38:17.063  INFO 18260 --- [           main] com.flyway.FlaywayApplication            : Starting FlaywayApplication using Java 1.8.0_71 on HYT211145187-01 with PID 18260 (G:\WorkSpace\springboot-test\flyway-test\target\classes started by 211145187 in G:\WorkSpace\springboot-test)
2022-11-01 16:38:17.064  INFO 18260 --- [           main] com.flyway.FlaywayApplication            : No active profile set, falling back to default profiles: default
2022-11-01 16:38:18.093  INFO 18260 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8015 (http)
2022-11-01 16:38:18.126  INFO 18260 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2022-11-01 16:38:18.126  INFO 18260 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.56]
2022-11-01 16:38:18.215  INFO 18260 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2022-11-01 16:38:18.215  INFO 18260 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1101 ms
2022-11-01 16:38:18.597  WARN 18260 --- [           main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'flyway' defined in class path resource [org/springframework/boot/autoconfigure/flyway/FlywayAutoConfiguration$FlywayConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.flywaydb.core.Flyway]: Factory method 'flyway' threw exception; nested exception is java.lang.BootstrapMethodError: java.lang.NoSuchMethodError: org.flywaydb.core.api.configuration.FluentConfiguration.ignoreMissingMigrations(Z)Lorg/flywaydb/core/api/configuration/FluentConfiguration;
2022-11-01 16:38:18.602  INFO 18260 --- [           main] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
2022-11-01 16:38:18.609  INFO 18260 --- [           main] ConditionEvaluationReportLoggingListener : 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2022-11-01 16:38:18.634 ERROR 18260 --- [           main] o.s.boot.SpringApplication               : Application run failed

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'flyway' defined in class path resource [org/springframework/boot/autoconfigure/flyway/FlywayAutoConfiguration$FlywayConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.flywaydb.core.Flyway]: Factory method 'flyway' threw exception; nested exception is java.lang.BootstrapMethodError: java.lang.NoSuchMethodError: org.flywaydb.core.api.configuration.FluentConfiguration.ignoreMissingMigrations(Z)Lorg/flywaydb/core/api/configuration/FluentConfiguration;
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:658) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:638) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1352) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1195) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:953) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918) ~[spring-context-5.3.15.jar:5.3.15]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.15.jar:5.3.15]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:732) [spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:414) [spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:302) [spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1303) [spring-boot-2.6.3.jar:2.6.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1292) [spring-boot-2.6.3.jar:2.6.3]
	at com.flyway.FlaywayApplication.main(FlaywayApplication.java:14) [classes/:na]
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.flywaydb.core.Flyway]: Factory method 'flyway' threw exception; nested exception is java.lang.BootstrapMethodError: java.lang.NoSuchMethodError: org.flywaydb.core.api.configuration.FluentConfiguration.ignoreMissingMigrations(Z)Lorg/flywaydb/core/api/configuration/FluentConfiguration;
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.3.15.jar:5.3.15]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:653) ~[spring-beans-5.3.15.jar:5.3.15]
	... 21 common frames omitted
Caused by: java.lang.BootstrapMethodError: java.lang.NoSuchMethodError: org.flywaydb.core.api.configuration.FluentConfiguration.ignoreMissingMigrations(Z)Lorg/flywaydb/core/api/configuration/FluentConfiguration;
	at org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration$FlywayConfiguration.configureIgnoredMigrations(FlywayAutoConfiguration.java:273) ~[spring-boot-autoconfigure-2.6.3.jar:2.6.3]
	at org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration$FlywayConfiguration.configureProperties(FlywayAutoConfiguration.java:213) ~[spring-boot-autoconfigure-2.6.3.jar:2.6.3]
	at org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration$FlywayConfiguration.flyway(FlywayAutoConfiguration.java:119) ~[spring-boot-autoconfigure-2.6.3.jar:2.6.3]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_71]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_71]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_71]
	at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_71]
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.3.15.jar:5.3.15]
	... 22 common frames omitted
Caused by: java.lang.NoSuchMethodError: org.flywaydb.core.api.configuration.FluentConfiguration.ignoreMissingMigrations(Z)Lorg/flywaydb/core/api/configuration/FluentConfiguration;
	at java.lang.invoke.MethodHandleNatives.resolve(Native Method) ~[na:1.8.0_71]
	at java.lang.invoke.MemberName$Factory.resolve(MemberName.java:962) ~[na:1.8.0_71]
	at java.lang.invoke.MemberName$Factory.resolveOrFail(MemberName.java:987) ~[na:1.8.0_71]
	at java.lang.invoke.MethodHandles$Lookup.resolveOrFail(MethodHandles.java:1390) ~[na:1.8.0_71]
	at java.lang.invoke.MethodHandles$Lookup.linkMethodHandleConstant(MethodHandles.java:1746) ~[na:1.8.0_71]
	at java.lang.invoke.MethodHandleNatives.linkMethodHandleConstant(MethodHandleNatives.java:477) ~[na:1.8.0_71]
	... 30 common frames omitted


Process finished with exit code 1