Question

我正在尝试从此职位开始工作 How can I have dynamic properties in go on the google app engine datastore

无法将数据插入数据存储区，仅创建ID

import (
    "log"
    "net/http"
    "time"

    "github.com/julienschmidt/httprouter"
    "google.golang.org/appengine"
    "google.golang.org/appengine/datastore"
)

type DynEnt map[string]interface{}

func (d *DynEnt) Load(props []datastore.Property) error {
    // Note: you might want to clear current values from the map or create a new map
    for _, p := range props {
        (*d)[p.Name] = p.Value
    }
    return nil
}

func (d *DynEnt) Save() (props []datastore.Property, err error) {
    for k, v := range *d {
        props = append(props, datastore.Property{Name: k, Value: v})
    }
    return nil, nil
}

//GetAccountHandler is to
func GetAccountHandler(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {

    c := appengine.NewContext(r)

    d := DynEnt{"email": "me@myhost.com", "time": time.Now()}
    log.Println("d=>", d)
    log.Println("&d=>", &d)
    k := datastore.NewIncompleteKey(c, "DynEntity", nil)
    key, err := datastore.Put(c, k, &d)
    log.Fatalf("%v %v", key, err)

}

Answer 1

my original answer中有一个错字，Save()末尾的返回值是复制/粘贴错误（来自通道版本）。正确的版本是：

func (d *DynEnt) Save() (props []datastore.Property, err error) {
    for k, v := range *d {
        props = append(props, datastore.Property{Name: k, Value: v})
    }
    return
}

请注意，return之后没有指定任何值，因为使用了命名结果参数。指定nil, nil不会返回内置在Save()中的切片。

还要在处理程序的末尾调用log.Fatalf()，这将终止您的应用程序。尝试使用log.Printf()。

无法在Google App Engine数据存储区中插入动态属性

1 个答案: