Question

我想查询一对多关系。我有以下结构：

type AppointmentsParticipants struct {
    AppointmentsID int `sql:",pk"`
    UserID int `sql:",pk"`
    Approved bool
    ReviewedAt time.Time
    ReviewedBy int
    Comment string
    Cancelled bool

}

type Appointments struct {
    ID int `sql:",pk"`
    Pending bool
    StartTime time.Time
    EndTime time.Time
    auditData
    InitialAppointmentID int
    SessionID string
    Type string
    AppointmentParticipants []*AppointmentsParticipants `json:"participants"`
}

我将查询编写如下：

var app Appointments
err = database.DB().
        Model(&app).
        Column("*").
        Where("appointments_participants.user_id = ?", id).
        Join("JOIN appointments_participants ON appointments.id = appointments_participants.appointments_id").
        Select()

这确实返回了Appointments结构的所有值，但AppointmentParticipants切片除外。它返回一个空切片。我接受了go-pg编写的查询，并在psql中进行了验证，该查询确实从约会对象表返回了一条记录。

这是输出：{140 true 2018-09-01 00:00:00 +0000 UTC 2018-09-01 01:00:00 +0000 UTC {2018-08-15 22:52:11.326775 +0000 UTC 5 0001-01-01 00:00:00 +0000 UTC 0} 0 Session []}

有趣的是，该查询确实返回错误：pg: can't find column=appointments_id in model=Appointments但是，我尝试使用struct标记来尝试解决此问题，但无济于事。

Answer 1

尝试这样的查询：

err = database.DB().
    Model(&app).
    Column("AppointmentsParticipants").
    Relation("AppointmentsParticipants", func(q *orm.Query) (*orm.Query, error) {
        return q.Where("user_id = ?", id), nil
    }).
    Select()

如果它不起作用，请尝试使用ID，其字段名称和标签，go-pg对此非常敏感。

如何用go-pg查询一对多关系

1 个答案: