GAE / Go：命名空间不起作用

Question

I am trying to store datastore record in namespace MyNameSpace with GAE/Go, but the code below not working.

import (
    "cloud.google.com/go/datastore"
    "github.com/gin-gonic/gin"
    "google.golang.org/appengine"
)

func Save(c *gin.Context, list []MyStruct) ([]MyStruct, error) {
    r := c.Request
    ctx := appengine.NewContext(r)
    ctx_with_namespace, err := appengine.Namespace(ctx, "MyNameSpace")
    if err != nil {
        return nil, err
    }

    client, err := datastore.NewClient(ctx_with_namespace, "MyProject")
    if err != nil {
        return nil, err
    }

    var keyList []*datastore.Key
    for _, v := range list {
        key := datastore.NameKey("MyStruct", v.ColA, nil)
        keyList = append(keyList, key)
    }

    _, err = client.PutMulti(ctx_with_namespace, keyList, list)

    return list,nil
}

This code creates records in the default namespace, not MyNameSpace.

Does cloud.google.com/go/datastore ignores namespace setting?

Answer 1

I found this document

November 8, 2016

Breaking changes to datastore: contexts no longer hold namespaces; instead you must set a key's namespace explicitly. Also, key functions have been changed and renamed.

The WithNamespace function has been removed. To specify a namespace in a Query, use the Query.Namespace method:

q := datastore.NewQuery("Kind").Namespace("ns")

All the fields of Key are exported. That means you can construct any Key with a struct literal:

k := &Key{Kind: "Kind", ID: 37, Namespace: "ns"}

I realized I should explicitly set namespace, but it is very inconvenient. I migrated to use google.golang.org/appengine/datastore