Go Gorm没有显示数据有很多

Question

I'm using http://gorm.io/docs/has_many.html to create several entries in one table owned by one team in another.

Team struct {
    ID             int64         `gorm:"primary_key" json:"Id"`
    PayingMemberID sql.NullInt64 `json:"PayingMemberId,int64"`
    PayingMember   *User
    Name           string `json:"Name"`

    Teamcoins          []Teamcoin `gorm:"foreignkey:TeamID"`
}

Teamcoin struct {
    ID     int64 `gorm:"primary_key" json:"Id"`
    Team   Team
    TeamID int64

    PeriodYear  int
    PeriodMonth int

    Coin int `json:"-"`
}

Then, I create an entry in the Team table like this:

teamcoin := Teamcoin{
    PeriodYear:        2018,
    PeriodMonth:       2,
    Coin:              12,
}

team := Team{
    Name : "Some Name",
    Microcoins: []Teamcoin{teamcoin},
}

The result, as expected, creates a team entry with ID. When I run next piece of code to get the info of all teams:

var t []Team
err := r.db.Preload("PayingMember").Find(&t).Error

And I show t, I get: {530071983 {0 false} Some Name { false} 0 0 0 [ ] 0 0 0 false}

Now, I might be omitting some info on the structure of the Team in this post, but anyway, I never get to show the information about the related TeamCoins even that the related information is created in the table.

[ ] is always empty and I'm expecting the TeamCoin information.

Answer 1

You probably should chain your preloads, do to get all of associacions you need to write

r.db.Preload("PayingMember").Preload("Teamcoins").Find(&t).Error