migrations: skip dropping constraint if a column is dropped

[ariga]

migrations: skip dropping constraint if a column is dropped

[a8m]

Fixed with #811. Thanks @amrnt 🙏

[a8m]

Thanks for reporting this @amrnt 🙏

[amrnt]

@a8m, I tried to change the StorageKey of an edge, it will drop and create the CONSTRAINT but the order of it will yield to errors as the same issue, the column is removed before the constraint:

 		edge.To("deliveries", Delivery.Type).
-			StorageKey(edge.Column("address_id")),
+			StorageKey(edge.Column("delivery_address_id")),

ALTER TABLE "deliveries"
  DROP COLUMN "address_id", 
  ADD COLUMN "delivery_address_id" character varying NOT NULL, 
  DROP CONSTRAINT "deliveries_addresses_deliveries", 
  ADD CONSTRAINT "deliveries_addresses_deliveries" FOREIGN KEY ("delivery_address_id") REFERENCES "addresses" ("id") ON DELETE NO ACTION;

[a8m]

Hey @amrnt 👋,
What Ent and Atlas versions do you use? Thanks

[amrnt]

latest I think,

	ariga.io/atlas v0.4.2-0.20220523090332-08a1147dfc44
	entgo.io/contrib v0.2.1-0.20220515130829-06b73685c304
	entgo.io/ent v0.10.2-0.20220521203114-1e05ccc28448

I checked other migration when fixed the original issue, the order is just fine. But this for the case where you change the column name.

[a8m]

OK, thanks. I'll give it a look tomorrow morning. For renaming, we plan to add an API to detect such changes (avoid drop and add).