QRM not invoking scanner

[Napam]

I essentially have the following:

package jetgen

type Facility string

package main()

type FacilitiesArray []jetgen.Facility

type Listing struct {
	// Various stuff here
	.
	.
	.
	Facilities FacilitiesArray
}

func GetListing(...) (*Listing, error) {
	selectStatement := SELECT(
		// stuff
	).FROM(
		t.Listings
	).WHERE(
		t.Listings.ID.EQ(UUID(parsedID)),
	)

	var dest Listing

	err = selectStatement.Query(db.DB, &dest)
	if err != nil {
		return nil, err
	}
        return Listing
}

The above works, but the Facilities just becomes an array with one element with the sql array in it, e.g.

"Facilities": ["{ELEVATOR,AIR_CONDITIONING,CHARGING,BROADBAND,GARAGE_PARKING,HIKING}"]

So I want to implement the scan interface in order to parse the thing. So I do

func (f *FacilitiesArray) Scan(src any) error {
	logging.Logger.Error().Any("src", src).Msg("AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA")
	fmt.Println("AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA")
        // This code doesn't make much sense at the moment, but I just want to get something to happen here
	temp := []jetgen.Facility{"QUIET", "VIEW"}
	*f = FacilitiesArray(temp)
	return nil
}

then the facilities I get is empty:

"Facilities": null

I also get no "AAAAAAAAAAAAAAAAAAAAAAAAA" in my console. So it seems like go-jet detects that there is a scanner available (because the facilities become null), but I can't see any evidence that the scanner is actually invoked.

[houtn11]

What is the database, driver and jet version?
Also how is Facility column defined in database?
And, how is Facility listed here:

selectStatement := SELECT(
	// stuff
).FROM(

[Napam]

The database is Postgres 17
Go 1.24.3 darwin/arm64
Jet is v2.13.0

The function is basically:

	facilitiesAgg := SELECT(
		t.ListingFacilities.ListingID,
		ARRAY_AGG(t.ListingFacilities.Facility).AS("facilities"),
	).FROM(
		t.ListingFacilities,
	).GROUP_BY(
		t.ListingFacilities.ListingID,
	).AsTable("agg")

	selectStatement := SELECT(
		facilitiesAgg.AllColumns().Except(
			t.ListingFacilities.ListingID,
		).As(""),
	).FROM(
		t.Listings.LEFT_JOIN(
			facilitiesAgg, t.Listings.ID.EQ(t.ListingFacilities.ListingID.From(facilitiesAgg)),
		),
	).WHERE(
		t.Listings.ID.EQ(UUID(parsedID)),
	)

	logger.Error().Func(func(e *zerolog.Event) {
		query, args := selectStatement.Sql()
		e.Str("query", query).Any("args", args).Str("id", id)
	}).Msg("Retrieving listing by ID")

	var dest Listing

	err = selectStatement.Query(db.DB, &dest)
	if err != nil {
		return nil, err
	}

	return &dest, nil

So, just to re-iterate, when I don't define any scan method on Facilities array I get something, so the QRM selector works. Once I add the scan method I get null.

[houtn11]

Since you added scan method FacilitiesArray is not complex object any more, but a field in Listing struct. So, facilities column has no destination. To fix it:

facilitiesAgg.AllColumns().Except(
	t.ListingFacilities.ListingID,
).As("listing.*"),

or

type Listing struct {
	// Various stuff here
	.
	.
	.
	Facilities FacilitiesArray `alias:"facilities"`
}

[houtn11]

Also, you can enable Stric Scan to catch situations like this early.

[Napam]

Since you added scan method FacilitiesArray is not complex object any more, but a field in Listing struct. So, facilities column has no destination. To fix it:

facilitiesAgg.AllColumns().Except(
	t.ListingFacilities.ListingID,
).As("listing.*"),

or

type Listing struct {
	// Various stuff here
	.
	.
	.
	Facilities FacilitiesArray `alias:"facilities"`
}

Thank you very much again, this fixed it.

Could you help me understand here, so once you add a Scan method, the type always becomes "non-complex"? Like, on the same level of string, int etc ...

Which then implies that doing As("FacilitiesArray.facilities") will not work, because "FacilitiesArray" won't be a "thing" during scanning?

I conjunciton, I did the As(""), which then in turn caused the resulting column to just be "facilities".

[houtn11]

Could you help me understand here, so once you add a Scan method, the type always becomes "non-complex"? Like, on the same level of string, int etc ...

Which then implies that doing As("FacilitiesArray.facilities") will not work, because "FacilitiesArray" won't be a "thing" during scanning?

I conjunciton, I did the As(""), which then in turn caused the resulting column to just be "facilities".

Yeah, exactly.