On Wed, Jan 18, 2023 at 9:03 PM Jeremy Smith <jeremy@xxxxxxxxxxxxxx> wrote: >> How to do this with two tables connected via one foreign key, that is >> explained a dozen times in Stackoverflow. But what if the tree is 50 >> tables and 120 foreign key columns? >> It can be done. But probably not manually. >> >> So, as this seems a very usual use-case for normalized data, is there >> any tooling available? Anywhere? (I searched, I didn't find.) > > I haven't used it, but this seems like the problem that Jailer is trying to solve: https://github.com/Wisser/Jailer Seems to dothe subsetting alright, but it doesn't mention the conflict-resolution for inserting into an already populated target schema. We've done something similar, merging many same-schema DBs into a single local SQLite DB (with conflicts, thus no constraints), iteratively resolving the conflicts (SK/PK and NK) per-table in topological order, propagating PK changes to FKs in child tables later. Then load the result into a full-constrained PostgreSQL DB. Clever'er minds can probably do it all in SQL, but we did it with a combination of imperative code and SQL. Not exactly your use case Peter, but close enough I think. I don't think a tool could have done what we did, it's too ad-hoc and specific to our use case. Took a while, and required lots of testing (unit tests, and functional QA tests). FWIW. --DD
