英文:
Go with GAE saved an object to datastore. when getting it back, the object has empty members
问题
我正在尝试使用GAE学习Go语言。
我创建了两个处理程序。一个用于将对象保存到数据存储中，另一个用于检索并输出到屏幕。问题是，当我从数据存储中检索UserAccount对象时，对象内的所有值都消失了。
任何帮助将不胜感激。
输出：
a/c count: 2 val: core.UserAccount{idString:"", deviceId:""} val: core.UserAccount{idString:"", deviceId:""}
type UserAccount struct {
idString string
deviceId string
}
func create_account(w http.ResponseWriter, r *http.Request) {
c := appengine.NewContext(r)
idstr := "ABCDEFGH"
devId := r.FormValue("deviceId")
newAccount := UserAccount{ idString: idstr, deviceId: devId,}
key := datastore.NewIncompleteKey(c, "UserAccount", nil)
_, err := datastore.Put(c, key, &newAccount)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
fmt.Fprintf(w, "val: %#v \n", newAccount)
}
func get_info(w http.ResponseWriter, r *http.Request) {
c := appengine.NewContext(r)
q := datastore.NewQuery("UserAccount")
accounts := make([]UserAccount, 0, 10)
if _, err := q.GetAll(c, &accounts); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
fmt.Fprintf(w, "a/c count: %v \n", len(accounts))
for i := 0; i < len(accounts); i++ {
fmt.Fprintf(w, "val: %#v \n", accounts[i])
}
}
英文:
I am trying to learn Go with GAE.
I have created 2 handlers. One for saving an object to datastore and the other retrieve it and output to screen. The problem is that when i retrieve the UserAccount object from datastore, every values inside the object are gone.
Any help would be appreciate.
Output:
a/c count: 2
val: core.UserAccount{idString:"", deviceId:""}
val: core.UserAccount{idString:"", deviceId:""}
type UserAccount struct {
idString string
deviceId string
}
func create_account(w http.ResponseWriter, r *http.Request) {
c := appengine.NewContext(r)
idstr := "ABCDEFGH"
devId := r.FormValue("deviceId")
newAccount := UserAccount{ idString: idstr, deviceId: devId,}
key := datastore.NewIncompleteKey(c, "UserAccount", nil)
_, err := datastore.Put(c, key, &newAccount)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
fmt.Fprintf(w, "val: %#v \n", newAccount)
}
func get_info(w http.ResponseWriter, r *http.Request) {
c := appengine.NewContext(r)
q := datastore.NewQuery("UserAccount")
accounts := make([]UserAccount, 0, 10)
if _, err := q.GetAll(c, &accounts); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
fmt.Fprintf(w, "a/c count: %v \n", len(accounts))
for i := 0; i < len(accounts); i++ {
fmt.Fprintf(w, "val: %#v \n", accounts[i])
}
}
答案1
得分: 5
如果数据存储API使用反射，我认为它确实使用了反射，它无法访问未导出的结构字段，即不以大写字母开头的字段名。
将它们导出，然后它应该可以工作。
英文:
If the datastore API uses reflection, which I presume it does, it cannot access struct fields that aren't exported, i.e. field names that do not begin with a capital letter.
Export them and it should work.
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