Please put this 6 month default in a constant. Or even better as a config variable.

Also, do we need to define a server-side max? Can the server properly handle the request if we get sent something like querySize=9999?

I belive grails allows for reading parameter values in the following way params.int("querySize", 6) where it casts the value to integer and second argument of this method is the default value

I would suggest moving those "2 days" etc. to static constants in Constants.groovy, as this might be reused in the future.

I guess the indentations are missing here

the only difference between those two queries if origin vs destination. Can we somehow pass it as a variable here so that we can reuse the query in both methods?

I am not sure if this is a good idea, I would rather say string concatenation in SQL is a thing that we should avoid.
As an example:
https://stackoverflow.com/questions/23179329/why-is-concatenating-sql-strings-a-bad-idea

If anyone else would like me to use the string concatenation here I can do it, but I am not a big fan, and that's the reason I didn't do it before.

I know cases when concatenation is a wrong idea, and this is why they introduced an ability to use params via :param and pass it as the second argument of a query method, but in this case:

1. you wouldn't use any variable that the user provides and that might break the query (e.g. drop database openboxes; 😆 ), but a variable that you would pass,
2. I was not really thinking about the concatenation, but rather passing it as param (if possible, probably not), or via ${variable}.

I'm not sure if any of those options are possible, hence I just asked if "we can".

Let's use backdatedShipments in these two names to match the indicators these are used for.

Do you mean axis or axes?

Axes is the plural of axis.

nvm, you're right, plural is axes