Auto-Rollback Generation

Writes the script that undoes a forward migration, and lists what cannot be undone instead of pretending it can.

What you provide

• Engine (required).
• Forward script (required).
• Preconditions, if any, such as "the table is empty".

No connection is read: only the script and your preconditions are sent.

What you get

• The rollback SQL.
• Operations that cannot be undone, such as dropping a table whose definition is not in the script, deleting or truncating rows, or dropping a column that held data.
• Notes on the choices made.