func ExampleGetMulti() {
ctx := Example_auth()
keys := []*datastore.Key{
datastore.NewKey(ctx, "Post", "post1", 0, nil),
datastore.NewKey(ctx, "Post", "post2", 0, nil),
datastore.NewKey(ctx, "Post", "post3", 0, nil),
}
posts := make([]Post, 3)
if err := datastore.GetMulti(ctx, keys, posts); err != nil {
log.Println(err)
}
}
func ExampleTransaction() {
ctx := Example_auth()
const retries = 3
// Increment a counter.
// See https://cloud.google.com/appengine/articles/sharding_counters for
// a more scalable solution.
type Counter struct {
Count int
}
key := datastore.NewKey(ctx, "counter", "CounterA", 0, nil)
for i := 0; i < retries; i++ {
tx, err := datastore.NewTransaction(ctx)
if err != nil {
break
}
var c Counter
if err := tx.Get(key, &c); err != nil && err != datastore.ErrNoSuchEntity {
break
}
c.Count++
if _, err := tx.Put(key, &c); err != nil {
break
}
// Attempt to commit the transaction. If there's a conflict, try again.
if _, err := tx.Commit(); err != datastore.ErrConcurrentTransaction {
break
}
}
}
func ExampleDelete() {
ctx := Example_auth()
key := datastore.NewKey(ctx, "Article", "articled1", 0, nil)
if err := datastore.Delete(ctx, key); err != nil {
log.Fatal(err)
}
}
func ExamplePutMulti_interfaceSlice() {
ctx := Example_auth()
keys := []*datastore.Key{
datastore.NewKey(ctx, "Post", "post1", 0, nil),
datastore.NewKey(ctx, "Post", "post2", 0, nil),
}
// PutMulti with an empty interface slice.
posts := []interface{}{
&Post{Title: "Post 1", PublishedAt: time.Now()},
&Post{Title: "Post 2", PublishedAt: time.Now()},
}
if _, err := datastore.PutMulti(ctx, keys, posts); err != nil {
log.Fatal(err)
}
}
func ExampleGet() {
ctx := Example_auth()
type Article struct {
Title string
Description string
Body string `datastore:",noindex"`
Author *datastore.Key
PublishedAt time.Time
}
key := datastore.NewKey(ctx, "Article", "articled1", 0, nil)
article := &Article{}
if err := datastore.Get(ctx, key, article); err != nil {
log.Fatal(err)
}
}
func ExamplePut() {
ctx := Example_auth()
type Article struct {
Title string
Description string
Body string `datastore:",noindex"`
Author *datastore.Key
PublishedAt time.Time
}
newKey := datastore.NewIncompleteKey(ctx, "Article", nil)
_, err := datastore.Put(ctx, newKey, &Article{
Title: "The title of the article",
Description: "The description of the article...",
Body: "...",
Author: datastore.NewKey(ctx, "Author", "jbd", 0, nil),
PublishedAt: time.Now(),
})
if err != nil {
log.Fatal(err)
}
}