Gorm Many2Many on existing db entities empty

Many2Many on existing db entities empty

The database and the table exist. Migrations and management remain in the third-party application. I migrate the structure using a script. Django application, if this is important.

Structs:

type DatahubMnemoEquipment struct {
    ID  int64  `gorm:"primaryKey" gorm:"column:id"`
    Works   []*DatahubDeviceParameter `gorm:"many2many:datahub_mnemoequipment_works;joinForeignKey:MnemoequipmentID;"`
}

func (DatahubMnemoEquipment) TableName() string {
    return "datahub_mnemoequipment"
}


type DatahubDeviceParameter struct {
    ID             int64 `gorm:"primaryKey" gorm:"column:id"`
    Tag            string `gorm:"column:tag"`
}

func (DatahubDeviceParameter) TableName() string {
    return "datahub_deviceparameter"
}

type DatahubMnemoequipmentWorks struct {
    ID                int64 `gorm:"primaryKey" gorm:"column:id"`
    MnemoequipmentID  int64 `gorm:"column:mnemoequipment_id"`
    Mnemoequipment    *DatahubMnemoEquipment
    DeviceparameterID int64 `gorm:"column:deviceparameter_id"`
    Deviceparameter   *DatahubDeviceParameter
}

func (DatahubMnemoequipmentWorks) TableName() string {
    return "datahub_mnemoequipment_works"
}

Query:

var equipments []db_models.DatahubMnemoEquipment
conn.Debug().Preload("Works").Preload(clause.Associations).Where("source_id = ?", source.Item.ID).Find(&equipments)
or simple
conn.Debug().Preload(clause.Associations).Where("source_id = ?", source.Item.ID).Find(&equipments)

Logs:

[30.720ms] [rows:20] SELECT * FROM "datahub_mnemoequipment_works" WHERE "datahub_mnemoequipment_works"."mnemoequipment_id" IN (60277,60278,60279,60280,60289,60281,60282)

[346.825ms] [rows:100] SELECT * FROM "datahub_mnemoequipment" WHERE source_id = 'BLU_4'

Debug:

With any tag configuration, the value is either nil or as in the picture above.

The document you expected this should be explained

https://gorm.io/docs/many_to_many.html

Expected answer

What am I doing wrong and a more detailed description or example with foreignKey, references, joinForeignKey, joinReferences

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