since you fetch it once in the StockMovementService, can't you just pass it as a param instead of re-fetching it here?

I am not sure why it's done here like that. OutboundStockMovement is just a representation and a "read-only" from a view. It is not associated, nor kept in the database (OutboundStockMovement is taken from stock_movement sql view). You already have StockMovement object here, hence there is no need to pull it again as an Outbound version of it from view. What I think is required is only to set

stockMovement?.shipment = null

and

stockMovement.requisition = null

So there is no attempt to save these removed objects at the end.

We have two domains: StockMovement and OutboundStockMovement. Both of them are looking the same, have the same id, etc. But two objects (one is created based on StockMovement, and the second is based on OutboundStockMovement) can exist independently. At the begging, I tried to delete only the shipment and requisition from the association, but I still got the error that both of them are associated.

@alannadolny as I showed on the call, the issue is that we first pull OutboundStockMovement in the controller and then pass params.id to deleteStockMovement and there is again refetch of StockMovement. When you change the type of parameter to def to allow passing OutboundStockMovement or StockMovement to that method and pass the first object to it and do all the required cleanup, then it works properly.

Thanks for that catch!

let's do it in the service layer, before any delete() (GORM's delete) happens (in case anyone forced to add flush there, because it'd break then)

what I mean is to add:

 stockMovement?.shipment = null

to line 354 (above shipmentService.deleteShipment)
and

stockMovement?.requisition = null

to line 356 (above requisitionService.deleteRequisition(stockMovement?.requisition))

or actually it sucks, because you then pass stockMovement.requisition which would be null to the deleteRequisition, so you should consider creating "a copy" of that object as:

Requisition requisition = stockMovement?.requisition

use it like that:

requisitionService.deleteRequisition(requisition)

but above that (between requisition and the delete call) do:

stockMovement?.requisition = null

which results in:

Requisition requisition = stockMovement?.requisition
stockMovement?.requisition = null
requisitionService.deleteRequisition(requisition)