Flyway offers you the possibility to hook into its lifecycle by using Callbacks. In order to use these callbacks, name a script after the callback name (ie. afterMigrate.sql) and drop it alongside your other scripts in your migrations folder.

Whenever the conditions are met, the callback script will be run. For example, an afterMigrate.sql script will execute after running the migrate command.

Callbacks are supported for a variety of different Flyway operations, such as migrate, undo, and clean. For a complete list of callback events, see Callback Events.

Note: Callbacks are not supported by Native Connectors.

Location

Flyway will discover SQL callbacks in the same manner as SQL migration scripts, based on the locations defined.

Whereas Java callbacks will be picked up from the classpath.

SQL Callbacks

The most convenient way to hook into Flyway's lifecycle is through SQL callbacks. These are simply sql files in the configured locations following a certain naming convention: the event name followed by the SQL migration suffix.

Placeholder replacement works just like it does for SQL migrations.

Optionally the callback may also include a description. In that case the callback name is composed of the event name, the separator, the description and the suffix. Example: beforeRepair__vacuum.sql.

Note: Flyway will also honor any sqlMigrationSuffixes you have configured, when scanning for SQL callbacks.

Java Callbacks

If SQL Callbacks aren't flexible enough for you, you have the option to implement the Callback interface yourself. You can even hook multiple Callback implementations in the lifecycle. Java callbacks have the additional flexibility that a single Callback implementation can handle multiple lifecycle events, and are therefore not bound by the SQL callback naming convention.

More info: Java-based Callbacks

Script Callbacks

Much like SQL callbacks, Flyway also supports the execution of callbacks written in a scripting language. The supported file extensions are the same as those supported by script migrations. For example, you could have a beforeRepair__vacuum.ps1 callback. Script callbacks give you much more flexibility and power during the migration lifecycle. Some of the things you can achieve are:

• Executing external tools between migrations
• Creating or cleaning local files for migrations to use

Callback ordering

When multiple callbacks for the same event are found, they are executed in the alphanumerical order. E.G.

beforeConnect__1.sql
beforeConnect__2.sql
beforeConnect__a.sql
beforeConnect__b.sql

Tutorial

Click here to see a tutorial on using callbacks.