Flyway repair with Spring Boot

there are several ways to perform a repair on the database. I personally prefer the simple SQL statement.

SQL Statement:

Just delete the row with the failed migration. After that you can run the migration again.

Run flyway directly

You can install Flyway local and run flyway repair in the console

Use the Flyway Maven Plugin

Add the Flyway Maven Plugin to your pom and run mvn flyway:repair. I don't think this contradict with the Spring Boot concept.

Extend Spring Boot

Spring Boot will call Flyway.migrate() to perform the database migration. If you would like more control, provide a @Bean that implements FlywayMigrationStrategy.

In the FlywayMigrationStrategy you can call the migrate or repair method from flyway. More Information is available in the Spring Boot Reference Guide.

I don't think the FlywayMigrationStrategy in the application is the right place to repair the database. A failed migration is a exception and should be handle outside the application.

Flyway Maven Plugin

Just to add this info to @Daniel's answer

1.

      ...
        <plugin>
            <groupId>org.flywaydb</groupId>
            <artifactId>flyway-maven-plugin</artifactId>
            <version>4.1.0</version>
            <configuration>
                <url>jdbc:mysql://localhost:3306</url>
                <user>root</user>
                <password>root</password>
                <schemas>
                    <schema>[your_schema]</schema>
                </schemas>
            </configuration>
        </plugin>
      ...

2.

mvn flyway:clean

3.

mvn flyway:repair

PS.: if the step 2 and 3 don't work change the order.

More info on maven goals: https://flywaydb.org/documentation/maven/

You can do it through code by declaring the following bean.

@Bean
public FlywayMigrationStrategy cleanMigrateStrategy() {
    return flyway -> {
        flyway.repair();
        flyway.migrate();
    };
}

When database migration fails, the migration is marked as failed in the schema history table (i.e flyway_schema_history) indicating manual database cleanup may be required. But if database supports DDL transactions, the migration is rolled back automatically and nothing is recorded in the schema history table. PostgreSQL, Amazon Redshift, MS SQL are few of the databases which support DDL transactions whereas Oracle Database, MySQL, MariaDB, Amazon Aurora does not support DDL transactions.

In case of failed migration entries, there are several options to repair it (only applicable for databases that do NOT support DDL transactions) as described by @daniel-käfer. I want to add another (may be easier way) to deal with failed migrations.

There are several callbacks supported by flyway, afterMigrateError is one of them. If we add a sql file with name afterMigrateError.sql then, it will be executed after each failed migrate runs. Therefore, we can simply create a file afterMigrateError.sql on default location of database migration folder (resources/db/migration) with sql command to remove failed migrations from flyway_schema_history table.

The sql command afterMigrateError.sql can be as mentioned below:

DELETE IGNORE FROM flyway_schema_history WHERE success=0;

This command looks for the table flyway_schema_history if it exists otherwise it will do no changes. Then it simply looks for the rows which has success column with 0 entry (actually this happen if migration fails , all successful migration will have value 1 in success column), then delete such entries. Now, we can simply change our latest migration file and correct it and run again.