Caused by: org.flywaydb.core.api.FlywayException: Validate failed. Migration Checksum mismatch for migration 2

Question

Flyway is comparing the checksum of the SQL script with that of the previously run checksum. This exception typically occurs if you change a SQL script that has already been applied by Flyway, thus causing a checksum mismatch.

If this is development, you can drop your database and start the migrations from scratch.

If you're in production, never edit SQL scripts that have already been applied. Only create new SQL scripts going forward.

Here the solution which worked for me when I had this issue in my local system.

1. Go to flyway_schema_history in your DB
2. Delete the row containing the sql migration script

I had the same issue and deleted the complete schema from the database, yet the issue remained.

I solved this by running the repair() command of flyway:

flyway.repair();

Alternatively with Flyway Maven plugin:

mvn flyway:repair

Maven plugin addition into pom.xml:

<plugin>
    <groupId>org.flywaydb</groupId>
    <artifactId>flyway-maven-plugin</artifactId>
    <version>5.2.4</version>
</plugin>

BTW: I did not find what exactly went wrong.

With Gradle (as per comment from Raf):

./gradlew flywayRepair

The best solution would be to do these steps :

1. Delete the file called - V2__create_shipwreck.sql, clean and build the project again.

2. Run the project again, login into h2 and delete the table called "schema_version".

   drop table schema_version;

3. Now make V2__create_shipwreck.sql file with ddl and rerun the project again.

4. Do remember this, add version 4.1.2 for flyway-core in pom.xml like

   <dependency>
       <groupId>org.flywaydb</groupId>
       <artifactId>flyway-core</artifactId>
       <version>4.1.2</version>
   </dependency>
   

It should work now. Hope this will help.

If you are sure that the modification in the SQL file has no impact on your existing schema, you can also update the checksum of the existing schema.

I did this following a slight change in the sql file.

Here is how I updated the checksum:

update flyway_schema_history set checksum = '-1934991199' where installed_rank = '1';