Composite key comprising foreign key not created correctly

[aol-nnov]

Your Question

I have following models:

type Country struct {
	NumCode uint `gorm:"primaryKey"`
	Name    string
	Code2   string `gorm:"size:2"`
	Code3   string `gorm:"size:3"`
}

import "overtime/pkg/model/types"

type ChangePeriod struct {
	ID uint `gorm:"primaryKey;autoIncrement"`

	CountryNumCode uint
	Country        Country `gorm:"index:idx_country_date_ranges,priority:1"`

	Period types.DateRange `gorm:"type:daterange; index:idx_country_date_ranges, type:gist, priority:2"`

	Comment string
}

During initial automigration despite table change_periods is created correctly with the foreign key country_num_code, I get the following error during index creation:

ERROR: unterminated quoted identifier at or near "")" (SQLSTATE 42601)
[rows:0] CREATE INDEX IF NOT EXISTS "idx_country_date_ranges" ON "change_periods" USING gist(","period")

Worth to mention, if I modify ChangePeriod as follows

type ChangePeriod struct {
	ID uint `gorm:"primaryKey;autoIncrement"`

	CountryNumCode uint `gorm:"index:idx_country_date_ranges,priority:1"`
	Country        Country 

	Period types.DateRange `gorm:"type:daterange; index:idx_country_date_ranges, type:gist, priority:2"`

	Comment string
}

Index is created successfully with the following SQL statement:

CREATE INDEX IF NOT EXISTS "idx_country_date_ranges" ON "change_periods" USING gist("country_num_code","period")

Do I get the whole idea of gorm tags wrong or is it a shortcoming/bug?

The document you expected this should be explained

Expected answer