Question content
When I try to automatically migrate the table according to my structure, I get this error, I don't know why I get this error
failed to parse value &models.model{id:0x0, createdat:time.date(1, time.january, 1, 0, 0, 0, 0, time.utc), updatedat:time.date(1, time.january, 1, 0, 0, 0, 0, time.utc), deletedat:, dogdata:[]models.dogdata(nil)}, got error invalid field found for struct github.com/dog-page/models.model's field dogdata: define a valid foreign key for relations or implement the valuer/scanner interface
I am new to golang language and gorm, especially when it comes to creating structures for raw json data, here is my intention of using gorm's structure:
type Model struct { ID uint `gorm:"primarykey:id" json:"id:_id"` CreatedAt time.Time `gorm:"column:created_at" json:"created_at"` UpdatedAt time.Time `gorm:"column:updated_at" json:"updated_at"` DeletedAt *time.Time `gorm:"column:deleted_at" json:"deleted_at"` DogData []DogData } type DogData struct { DogDataID uint Name string `json:"name"` Life_Span string `json:"life_span"` Temperaments string `json:"temperament"` Weight datatypes.JSON `json:"weight"` Height datatypes.JSON `json:"height"` Image datatypes.JSON `json:"image"` } type Weight struct { Imperial string `json:"imperial"` Metric string `json:"metric"` } type Height struct { Imperial string `json:"imperial"` Metric string `json:"metric"` } type Image struct { URL string `json:"url"` }
Solution
Model’s fields dogdata: Define valid foreign keys for relationships
The model has a one-to-many relationship with dogdata, and gorm cannot recognize foreign keys.
You need to specify the column to store model.id
in dogdata
(gorm looks for modelid by default),
type model struct { id uint `gorm:"primarykey:id" json:"id:_id"` ... dogdata []dogdata } type dogdata struct { modelid uint dogdataid uint ... } //create table `dog_data` (`model_id` integer,`dog_data_id` integer,`name` text,`life_span` text,`temperaments` text,constraint `fk_models_dog_data` foreign key (`model_id`) references `models`(`id`))
Or if you want to use another column instead of specifying the column using foreignkey tag
type model struct { id uint `gorm:"primarykey:id" json:"id:_id"` ... dogdata []dogdata `gorm:"foreignkey:dogdataid"` } type dogdata struct { dogdataid uint ... } //create table `dog_data` (`model_id` integer,`dog_data_id` integer,`name` text,`life_span` text,`temperaments` text,constraint `fk_models_dog_data` foreign key (`dog_data_id`) references `models`(`id`))
Not sure about the use case, but I think dogdata
can be simplified to, removing the model
structure entirely since it is the same as gorm.model
type DogData struct { gorm.Model Name string `json:"name"` ... }
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