我是GO Gorm协会的新手。我有这样的代码:
package main
import (
_ "database/sql"
"fmt"
_ "github.com/go-sql-driver/mysql"
"github.com/jinzhu/gorm"
)
type User struct {
ID uint `gorm:"primary_key"`
Name string
}
type Event struct {
ID uint `gorm:"primary_key"`
EventName string
Users []User `gorm:"many2many:event_reviews;"`
}
type EventReview struct {
UserID uint
EventID uint
Rating float64
Review string
}
func main() {
db, _ := gorm.Open("mysql", "root:@tcp(127.0.0.1:3306)/test1?charset=utf8&parseTime=True")
defer db.Close()
db.DropTableIfExists(&EventReview{}, &Event{}, &User{})
db.AutoMigrate(&User{}, &Event{}, &EventReview{})
//All foreign keys need to define here
db.Model(EventReview{}).AddForeignKey("user_id", "users(id)", "CASCADE", "CASCADE")
db.Model(EventReview{}).AddForeignKey("event_id", "events(id)", "CASCADE", "CASCADE")
user := User{Name: "John"}
db.Create(&user)
event := Event{EventName: "Learning Go"}
db.Create(&event)
eventReview := EventReview{UserID: user.ID, EventID: event.ID, Rating: 2.5, Review: "ExcelentEvent"}
db.Create(&eventReview)
//Fetching
eventFetch := &Event{}
db.Preload("Users").First(&eventFetch)
fmt.Println(eventFetch)
}
我有结构用户,事件,事件审核。事件与用户有很多关系。我已经阅读了许多人读过许多人,但我感到困惑以获取事件审查的数据。
结果println:
&{1 Learning Go [{1 John}]}
结果预期:
&{1 Learning Go [{1 John 2.5 ExcelentEvent}]}
如何获得预期的结果?使用许多关系表是我错的吗?
使用相关方法:
db.Model(&dm.User{}).Related(&dm.EventReview{}, "user_id")
res:=QueryByStructExample(dm.User{Email: "email@example.com})
func QueryByStructExample(userStruct User) []User {
var results []dm.User
GormDB.Where(userStruct).Find(&results)
return results
}