I hope the poster will learn about transactions at some point. Postgres even lets you alter the schema within a transaction.
What I learned, once upon a time, is that with a database, you shouldn't delete data you want to keep. If you want to keep something, you use SQL's fine UPDATE to update it, you don't delete it. Databases work best if you tell them to do what you want them to do, as a single transaction.
What I learned, once upon a time, is that with a database, you shouldn't delete data you want to keep. If you want to keep something, you use SQL's fine UPDATE to update it, you don't delete it. Databases work best if you tell them to do what you want them to do, as a single transaction.