after go gorm select, the result set or all struct are returned, except that the other fields are empty

the environmental background of the problems and what methods you have tried

related codes

db.Debug (). Where (s). Select ([] string {"id", "username", "phone"}). Find (& user)

type User struct {

gorm.Model
Username string `json:"username"`
Phone string `json:"phone"`
Type int8 `json:"type"`
Order []Order `gorm:"ForeignKey:UId"`   // hasMany 
CreditCard *CreditCard `gorm:"foreignkey:CardID"`
CardID uint

}

actual results

[
{
"id": 3,
"created_at": "0001-01-01T00:00:00Z",
"updated_at": "0001-01-01T00:00:00Z",
"deleted_at": null,
"username": "hello",
"phone": "18672858778",
"type": 0,
"Order": null,
"CreditCard": null,
"CardID": 0
},
{
"id": 6,
"created_at": "0001-01-01T00:00:00Z",
"updated_at": "0001-01-01T00:00:00Z",
"deleted_at": null,
"username": "hello",
"phone": "18672858778",
"type": 0,
"Order": null,
"CreditCard": null,
"CardID": 0
},
{
"id": 9,
"created_at": "0001-01-01T00:00:00Z",
"updated_at": "0001-01-01T00:00:00Z",
"deleted_at": null,
"username": "hello",
"phone": "18672858779",
"type": 0,
"Order": null,
"CreditCard": null,
"CardID": 0
},
{
"id": 12,
"created_at": "0001-01-01T00:00:00Z",
"updated_at": "0001-01-01T00:00:00Z",
"deleted_at": null,
"username": "hello",
"phone": "18672858779",
"type": 0,
"Order": null,
"CreditCard": null,
"CardID": 0
}
]

expected results

[{
"id":6,
"username":"hello",
"phone":"18672858779"
},
{
"id":9,
"username":"hello",
"phone":"18672858779"
}
]