During development you'll occasionally need an undo script that drops a group of tables, or you might need to truncate a group of tables and then insert fresh data in order to run some tests. Unless you perform the required actions in the correct dependency order, you'll be tripped up by foreign key constraint violations. This article provides a SQL function that returns the list of tables in the correct dependency order. Read more
Rollback scripts are designed to allow us to recover safely from a failed deployment that leaves the database in an indeterminate state. They must check exactly what needs to be reverted before doing so. If you work with an RDBMS that cannot support transaction DDL rollback they are vital. This article proposes a strategy where you create and test a rollback file, at the same time as the forward migration, and reuse it as a Flyway undo script. Read more
How to auto-generate first-cut undo scripts for every Flyway migration. For every new version of a database created by a Flyway versioned migration, we compare it to a 'source' directory containing object-level build scripts for the previous version. The SQL Compare engine does the rest, producing the associated undo script that will revert the database to the previous version, if required. Read more
Flyway Teams has an Undo facility that enables you to roll back one or more migrations. This article demonstrates how it works and explains how Undo migrations make testing migration scripts easier and branch-based development simpler. Read more
This article explains the fastest ways to restore the previous version of the database, to recover from a failed Flyway migration that leaves the database in an indeterminate state, and then how to adapt your database development process to avoid these problems. Read more