invalid field found for struct ()’s field Enclosure: define a valid foreign key for relations or implement the Valuer/Scanner interface
I’ve been getting this error in the project I’ve coded with Go, and I haven’t been able to figure out the source of the problem for a long time.

In the project where I perform database operations using GORM, I get this error when trying to fetch data from relational tables. The GORM query causing the error is:

// GET ALL ENCLOSURES
func (enclosures *Enclosure) GetAllEnclosures(db *gorm.DB, companyId uint) ([]struct {
    Enclosure     Enclosure
    MapRegionName string
}, error) {
    var enclosuresList []struct {
        Enclosure     Enclosure
        MapRegionName string
    }
    result := db.Table("enclosures").
        Select("enclosures.*, map_regions.name as map_region_name").
        Joins("LEFT JOIN map_regions ON map_regions.id = enclosures.map_region_fk").
        Where("enclosures.company_fk = ? AND enclosures.deleted_at IS NULL", companyId).
        Order("enclosures.created_at DESC").
        Scan(&enclosuresList)

    if result.Error != nil {
        return nil, result.Error
    }
    return enclosuresList, nil
}

With this function, I want to join the map_region_fk in the enclosures table with the map_regions table to add the map region name to the query output. “When I run this function, I get the error: ‘invalid field found for struct ()’s field Enclosure: define a valid foreign key for relations or implement the Valuer/Scanner interface.'”

Enclosure Struct:

type Enclosure struct {
    gorm.Model
    ID          uint    `gorm:"primaryKey"`
    Name        string  `gorm:"not null"`
    Description string  `gorm:"not null"`
    Period      int64   `gorm:"not null"`
    CompanyFk   uint    `gorm:"not null"`
    Company     Company `gorm:"foreignKey:CompanyFk;constraint:OnUpdate:CASCADE,OnDelete:CASCADE;"`
    MaxSenors   int64   `gorm:"default:20"`
    Latitude    float64 `gorm:"not null"`
    Longitude   float64 `gorm:"not null"`
    MapRegionFk uint      `gorm:"not null"`
    MapRegion   MapRegion `gorm:"foreignKey:MapRegionFk;constraint:OnUpdate:CASCADE,OnDelete:CASCADE;"`
    Duration    int64     `gorm:"not null"`
    Status      int16     `gorm:"default:1"`
    CreatedAt   time.Time `gorm:"default:current_timestamp"`
    UpdatedAt   time.Time
    DeletedAt   gorm.DeletedAt `gorm:"index"`
}

MapRegion Struct:

type MapRegion struct {
    gorm.Model
    ID           uint      `gorm:"primaryKey"`
    Name         string    `gorm:"not null"`
    MapFk        uint      `gorm:"not null"`
    Map          Map       `gorm:"foreignKey:MapFk;constraint:OnUpdate:CASCADE,OnDelete:CASCADE;"`
    MaxEnclosure int64     `gorm:"default:10"`
    Status       int16     `gorm:"default:1"`
    CreatedAt    time.Time `gorm:"default:current_timestamp"`
    UpdatedAt    time.Time
    DeletedAt    gorm.DeletedAt `gorm:"index"`
}

Map Struct:

type Map struct {
    gorm.Model
    ID         uint        `gorm:"primaryKey"`
    Name       string      `gorm:"not null"`
    CompanyFk  uint        `gorm:"not null"`
    Company    Company     `gorm:"foreignKey:CompanyFk"`
    MaxRegion  int64       `gorm:"default:5"`
    Status     int16       `gorm:"default:1"`
    MapRegions []MapRegion `gorm:"foreignKey:MapFk;references:ID"`
    CreatedAt  time.Time   `gorm:"default:current_timestamp"`
    UpdatedAt  time.Time
    DeletedAt  gorm.DeletedAt `gorm:"index"`
}

Company Struct:

type Company struct {
    gorm.Model
    ID          uint           `gorm:"primaryKey"`
    Name        string         `gorm:"not null"`
    Email       string         `gorm:"not null;unique"`
    PhoneNumber string         `gorm:"not null"`
    UserID      int64          `gorm:"not null"`
    CountryFk   int64          `gorm:"not null"`
    Country     models.Country `gorm:"foreignKey:CountryFk;constraint:OnUpdate:CASCADE,OnDelete:CASCADE;"`
    CityFk      int64          `gorm:"not null"`
    City        models.City    `gorm:"foreignKey:CityFk;constraint:OnUpdate:CASCADE,OnDelete:CASCADE;"`
    TaxOffice   string         `gorm:"not null"`
    TaxId       string         `gorm:"not null"`
    Status      int16
    CreatedAt   time.Time `gorm:"default:current_timestamp"`
    UpdatedAt   time.Time
    DeletedAt   gorm.DeletedAt `gorm:"index"`
}

I defined references for foreign keys in every struct I created, but I still kept encountering the same issue. I also tried dropping and recreating all the tables, but that didn’t solve the problem either.