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snippet_test.go
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snippet_test.go
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// Copyright 2019 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package datastore_snippets contains snippet code for the Cloud Datastore API.
// The code is not runnable.
package datastore_snippets
import (
"bytes"
"context"
"fmt"
"io"
"log"
"strings"
"testing"
"time"
"cloud.google.com/go/datastore"
"github.com/GoogleCloudPlatform/golang-samples/internal/testutil"
"google.golang.org/api/iterator"
)
type Task struct {
Category string
Done bool
Priority int
Description string `datastore:",noindex"`
PercentComplete float64
Created time.Time
Tags []string
Collaborators []string
}
func SnippetNewIncompleteKey() {
// [START datastore_incomplete_key]
// A complete key is assigned to the entity when it is Put.
taskKey := datastore.IncompleteKey("Task", nil)
// [END datastore_incomplete_key]
_ = taskKey // Use the task key for datastore operations.
}
func SnippetNewKey() {
// [START datastore_named_key]
taskKey := datastore.NameKey("Task", "sampletask", nil)
// [END datastore_named_key]
_ = taskKey // Use the task key for datastore operations.
}
func SnippetNewKey_withParent() {
// [START datastore_key_with_parent]
parentKey := datastore.NameKey("TaskList", "default", nil)
taskKey := datastore.NameKey("Task", "sampleTask", parentKey)
// [END datastore_key_with_parent]
_ = taskKey // Use the task key for datastore operations.
}
func SnippetNewKey_withMultipleParents() {
// [START datastore_key_with_multilevel_parent]
userKey := datastore.NameKey("User", "alice", nil)
parentKey := datastore.NameKey("TaskList", "default", userKey)
taskKey := datastore.NameKey("Task", "sampleTask", parentKey)
// [END datastore_key_with_multilevel_parent]
_ = taskKey // Use the task key for datastore operations.
}
func SnippetClient_Put() {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
// [START datastore_entity_with_parent]
parentKey := datastore.NameKey("TaskList", "default", nil)
key := datastore.IncompleteKey("Task", parentKey)
task := Task{
Category: "Personal",
Done: false,
Priority: 4,
Description: "Learn Cloud Datastore",
}
// A complete key is assigned to the entity when it is Put.
var err error
key, err = client.Put(ctx, key, &task)
// [END datastore_entity_with_parent]
_ = err // Make sure you check err.
}
func Snippet_properties() {
// [START datastore_properties]
type Task struct {
Category string
Done bool
Priority int
Description string `datastore:",noindex"`
PercentComplete float64
Created time.Time
}
task := &Task{
Category: "Personal",
Done: false,
Priority: 4,
Description: "Learn Cloud Datastore",
PercentComplete: 10.0,
Created: time.Now(),
}
// [END datastore_properties]
_ = task // Use the task in a datastore Put operation.
}
func Snippet_sliceProperties() {
// [START datastore_array_value]
type Task struct {
Tags []string
Collaborators []string
}
task := &Task{
Tags: []string{"fun", "programming"},
Collaborators: []string{"alice", "bob"},
}
// [END datastore_array_value]
_ = task // Use the task in a datastore Put operation.
}
func Snippet_basicEntity() {
// [START datastore_basic_entity]
type Task struct {
Category string
Done bool
Priority float64
Description string `datastore:",noindex"`
PercentComplete float64
Created time.Time
}
task := &Task{
Category: "Personal",
Done: false,
Priority: 4,
Description: "Learn Cloud Datastore",
PercentComplete: 10.0,
Created: time.Now(),
}
// [END datastore_basic_entity]
_ = task // Use the task in a datastore Put operation.
}
func SnippetClient_Put_upsert() {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
task := &Task{} // Populated with appropriate data.
// [START datastore_upsert]
key := datastore.IncompleteKey("Task", nil)
key, err := client.Put(ctx, key, task)
// [END datastore_upsert]
_ = err // Make sure you check err.
_ = key // key is the complete key for the newly stored task
}
func SnippetTransaction_insert() {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
task := Task{} // Populated with appropriate data.
// [START datastore_insert]
taskKey := datastore.NameKey("Task", "sampleTask", nil)
_, err := client.RunInTransaction(ctx, func(tx *datastore.Transaction) error {
// We first check that there is no entity stored with the given key.
var empty Task
if err := tx.Get(taskKey, &empty); err != datastore.ErrNoSuchEntity {
return err
}
// If there was no matching entity, store it now.
_, err := tx.Put(taskKey, &task)
return err
})
// [END datastore_insert]
_ = err // Make sure you check err.
}
func SnippetClient_Get() {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
// [START datastore_lookup]
var task Task
taskKey := datastore.NameKey("Task", "sampleTask", nil)
err := client.Get(ctx, taskKey, &task)
// [END datastore_lookup]
_ = err // Make sure you check err.
}
func SnippetTransaction_update() {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
// [START datastore_update]
taskKey := datastore.NameKey("Task", "sampleTask", nil)
tx, err := client.NewTransaction(ctx)
if err != nil {
log.Fatalf("client.NewTransaction: %v", err)
}
var task Task
if err := tx.Get(taskKey, &task); err != nil {
log.Fatalf("tx.Get: %v", err)
}
task.Priority = 5
if _, err := tx.Put(taskKey, &task); err != nil {
log.Fatalf("tx.Put: %v", err)
}
if _, err := tx.Commit(); err != nil {
log.Fatalf("tx.Commit: %v", err)
}
// [END datastore_update]
}
func SnippetClient_Delete() {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
// [START datastore_delete]
key := datastore.NameKey("Task", "sampletask", nil)
err := client.Delete(ctx, key)
// [END datastore_delete]
_ = err // Make sure you check err.
}
func SnippetClient_PutMulti() {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
// [START datastore_batch_upsert]
tasks := []*Task{
{
Category: "Personal",
Done: false,
Priority: 4,
Description: "Learn Cloud Datastore",
},
{
Category: "Personal",
Done: false,
Priority: 5,
Description: "Integrate Cloud Datastore",
},
}
keys := []*datastore.Key{
datastore.IncompleteKey("Task", nil),
datastore.IncompleteKey("Task", nil),
}
keys, err := client.PutMulti(ctx, keys, tasks)
// [END datastore_batch_upsert]
_ = err // Make sure you check err.
_ = keys // keys now has the complete keys for the newly stored tasks.
}
func SnippetClient_GetMulti() {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
// [START datastore_batch_lookup]
var taskKeys []*datastore.Key // Populated with incomplete keys.
tasks := make([]*Task, len(taskKeys))
err := client.GetMulti(ctx, taskKeys, &tasks)
// [END datastore_batch_lookup]
_ = err // Make sure you check err.
}
func SnippetClient_DeleteMulti() {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
var taskKeys []*datastore.Key // Populated with incomplete keys.
// [START datastore_batch_delete]
err := client.DeleteMulti(ctx, taskKeys)
// [END datastore_batch_delete]
_ = err // Make sure you check err.
}
func SnippetQuery_basic() {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
// [START datastore_basic_query]
query := datastore.NewQuery("Task").
FilterField("Done", "=", false).
FilterField("Priority", ">=", 4).
Order("-Priority")
// [END datastore_basic_query]
// [START datastore_run_query]
it := client.Run(ctx, query)
for {
var task Task
_, err := it.Next(&task)
if err == iterator.Done {
break
}
if err != nil {
log.Fatalf("Error fetching next task: %v", err)
}
fmt.Printf("Task %q, Priority %d\n", task.Description, task.Priority)
}
// [END datastore_run_query]
}
func SnippetQuery_propertyFilter() {
// [START datastore_property_filter]
query := datastore.NewQuery("Task").FilterField("Done", "=", false)
// [END datastore_property_filter]
_ = query // Use client.Run or client.GetAll to execute the query.
}
func SnippetQuery_compositeFilter() {
// [START datastore_composite_filter]
query := datastore.NewQuery("Task").
FilterField("Done", "=", false).
FilterField("Priority", "=", 4)
// [END datastore_composite_filter]
_ = query // Use client.Run or client.GetAll to execute the query.
}
func SnippetQuery_keyFilter() {
// [START datastore_key_filter]
key := datastore.NameKey("Task", "someTask", nil)
query := datastore.NewQuery("Task").FilterField("__key__", ">", key)
// [END datastore_key_filter]
_ = query // Use client.Run or client.GetAll to execute the query.
}
func SnippetQuery_sortAscending() {
// [START datastore_ascending_sort]
query := datastore.NewQuery("Task").Order("created")
// [END datastore_ascending_sort]
_ = query // Use client.Run or client.GetAll to execute the query.
}
func SnippetQuery_sortDescending() {
// [START datastore_descending_sort]
query := datastore.NewQuery("Task").Order("-created")
// [END datastore_descending_sort]
_ = query // Use client.Run or client.GetAll to execute the query.
}
func SnippetQuery_sortMulti() {
// [START datastore_multi_sort]
query := datastore.NewQuery("Task").Order("-priority").Order("created")
// [END datastore_multi_sort]
_ = query // Use client.Run or client.GetAll to execute the query.
}
func SnippetQuery_kindless() {
var lastSeenKey *datastore.Key
// [START datastore_kindless_query]
query := datastore.NewQuery("").FilterField("__key__", ">", lastSeenKey)
// [END datastore_kindless_query]
_ = query // Use client.Run or client.GetAll to execute the query.
}
func SnippetQuery_Ancestor() {
// [START datastore_ancestor_query]
ancestor := datastore.NameKey("TaskList", "default", nil)
query := datastore.NewQuery("Task").Ancestor(ancestor)
// [END datastore_ancestor_query]
_ = query // Use client.Run or client.GetAll to execute the query.
}
func SnippetQuery_Project() {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
// [START datastore_projection_query]
query := datastore.NewQuery("Task").Project("Priority", "PercentComplete")
// [END datastore_projection_query]
// [START datastore_run_query_projection]
var priorities []int
var percents []float64
it := client.Run(ctx, query)
for {
var task Task
if _, err := it.Next(&task); err == iterator.Done {
break
} else if err != nil {
log.Fatal(err)
}
priorities = append(priorities, task.Priority)
percents = append(percents, task.PercentComplete)
}
// [END datastore_run_query_projection]
}
func SnippetQuery_KeysOnly() {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
// [START datastore_keys_only_query]
query := datastore.NewQuery("Task").KeysOnly()
// [END datastore_keys_only_query]
keys, err := client.GetAll(ctx, query, nil)
_ = err // Make sure you check err.
_ = keys // Keys contains keys for all stored tasks.
}
func SnippetQuery_DistinctOn() {
// [START datastore_distinct_on_query]
query := datastore.NewQuery("Task").
Project("Priority", "Category").
DistinctOn("Category").
Order("Category").Order("Priority")
// [END datastore_distinct_on_query]
_ = query // Use client.Run or client.GetAll to execute the query.
}
func SnippetQuery_Filter_arrayInequality() {
// [START datastore_array_value_inequality_range]
query := datastore.NewQuery("Task").
FilterField("Tag", ">", "learn").
FilterField("Tag", "<", "math")
// [END datastore_array_value_inequality_range]
_ = query // Use client.Run or client.GetAll to execute the query.
}
func SnippetQuery_Filter_arrayEquality() {
// [START datastore_array_value_equality]
query := datastore.NewQuery("Task").
FilterField("Tag", "=", "fun").
FilterField("Tag", "=", "programming")
// [END datastore_array_value_equality]
_ = query // Use client.Run or client.GetAll to execute the query.
}
func SnippetQuery_Filter_inequality() {
// [START datastore_inequality_range]
query := datastore.NewQuery("Task").
FilterField("Created", ">", time.Date(1990, 1, 1, 0, 0, 0, 0, time.UTC)).
FilterField("Created", "<", time.Date(2000, 1, 1, 0, 0, 0, 0, time.UTC))
// [END datastore_inequality_range]
_ = query // Use client.Run or client.GetAll to execute the query.
}
func SnippetQuery_Filter_invalidInequality() {
// [START datastore_inequality_invalid]
query := datastore.NewQuery("Task").
FilterField("Created", ">", time.Date(1990, 1, 1, 0, 0, 0, 0, time.UTC)).
FilterField("Priority", ">", 3)
// [END datastore_inequality_invalid]
_ = query // The query is invalid.
}
func SnippetQuery_Filter_mixed() {
// [START datastore_equal_and_inequality_range]
query := datastore.NewQuery("Task").
FilterField("Priority", "=", 4).
FilterField("Done", "=", false).
FilterField("Created", ">", time.Date(1990, 1, 1, 0, 0, 0, 0, time.UTC)).
FilterField("Created", "<", time.Date(2000, 1, 1, 0, 0, 0, 0, time.UTC))
// [END datastore_equal_and_inequality_range]
_ = query // Use client.Run or client.GetAll to execute the query.
}
func SnippetQuery_inequalitySort() {
// [START datastore_inequality_sort]
query := datastore.NewQuery("Task").
FilterField("Priority", ">", 3).
Order("Priority").
Order("Created")
// [END datastore_inequality_sort]
_ = query // Use client.Run or client.GetAll to execute the query.
}
func SnippetQuery_invalidInequalitySortA() {
// [START datastore_inequality_sort_invalid_not_same]
query := datastore.NewQuery("Task").
FilterField("Priority", ">", 3).
Order("Created")
// [END datastore_inequality_sort_invalid_not_same]
_ = query // The query is invalid.
}
func SnippetQuery_invalidInequalitySortB() {
// [START datastore_inequality_sort_invalid_not_first]
query := datastore.NewQuery("Task").
FilterField("Priority", ">", 3).
Order("Created").
Order("Priority")
// [END datastore_inequality_sort_invalid_not_first]
_ = query // The query is invalid.
}
func SnippetQuery_Limit() {
// [START datastore_limit]
query := datastore.NewQuery("Task").Limit(5)
// [END datastore_limit]
_ = query // Use client.Run or client.GetAll to execute the query.
}
func SnippetIterator_Cursor() {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
// [START datastore_cursor_paging]
// cursorStr is a cursor to start querying at.
cursorStr := ""
const pageSize = 5
query := datastore.NewQuery("Tasks").Limit(pageSize)
if cursorStr != "" {
cursor, err := datastore.DecodeCursor(cursorStr)
if err != nil {
log.Fatalf("Bad cursor %q: %v", cursorStr, err)
}
query = query.Start(cursor)
}
// Read the tasks.
var tasks []Task
var task Task
it := client.Run(ctx, query)
_, err := it.Next(&task)
for err == nil {
tasks = append(tasks, task)
_, err = it.Next(&task)
}
if err != iterator.Done {
log.Fatalf("Failed fetching results: %v", err)
}
// Get the cursor for the next page of results.
// nextCursor.String can be used as the next page's token.
nextCursor, err := it.Cursor()
// [END datastore_cursor_paging]
_ = err // Check the error.
_ = nextCursor // Use nextCursor.String as the next page's token.
}
func SnippetQuery_EventualConsistency() {
// [START datastore_eventual_consistent_query]
ancestor := datastore.NameKey("TaskList", "default", nil)
query := datastore.NewQuery("Task").Ancestor(ancestor).EventualConsistency()
// [END datastore_eventual_consistent_query]
_ = query // Use client.Run or client.GetAll to execute the query.
}
func SnippetQuery_unindexed() {
// [START datastore_unindexed_property_query]
query := datastore.NewQuery("Tasks").
FilterField("Description", "=", "A task description")
// [END datastore_unindexed_property_query]
_ = query // Use client.Run or client.GetAll to execute the query.
}
func Snippet_explodingProperties() {
// [START datastore_exploding_properties]
task := &Task{
Tags: []string{"fun", "programming", "learn"},
Collaborators: []string{"alice", "bob", "charlie"},
Created: time.Now(),
}
// [END datastore_exploding_properties]
_ = task // Use the task in a datastore Put operation.
}
func Snippet_Transaction() {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
var to, from *datastore.Key
// [START datastore_transactional_update]
type BankAccount struct {
Balance int
}
const amount = 50
keys := []*datastore.Key{to, from}
tx, err := client.NewTransaction(ctx)
if err != nil {
log.Fatalf("client.NewTransaction: %v", err)
}
accs := make([]BankAccount, 2)
if err := tx.GetMulti(keys, accs); err != nil {
tx.Rollback()
log.Fatalf("tx.GetMulti: %v", err)
}
accs[0].Balance += amount
accs[1].Balance -= amount
if _, err := tx.PutMulti(keys, accs); err != nil {
tx.Rollback()
log.Fatalf("tx.PutMulti: %v", err)
}
if _, err = tx.Commit(); err != nil {
log.Fatalf("tx.Commit: %v", err)
}
// [END datastore_transactional_update]
}
func Snippet_Client_RunInTransaction() {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
var to, from *datastore.Key
// [START datastore_transactional_retry]
type BankAccount struct {
Balance int
}
const amount = 50
_, err := client.RunInTransaction(ctx, func(tx *datastore.Transaction) error {
keys := []*datastore.Key{to, from}
accs := make([]BankAccount, 2)
if err := tx.GetMulti(keys, accs); err != nil {
return err
}
accs[0].Balance += amount
accs[1].Balance -= amount
_, err := tx.PutMulti(keys, accs)
return err
})
// [END datastore_transactional_retry]
_ = err // Check error.
}
func SnippetTransaction_getOrCreate() {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
key := datastore.NameKey("Task", "sampletask", nil)
// [START datastore_transactional_get_or_create]
_, err := client.RunInTransaction(ctx, func(tx *datastore.Transaction) error {
var task Task
if err := tx.Get(key, &task); err != datastore.ErrNoSuchEntity {
return err
}
_, err := tx.Put(key, &Task{
Category: "Personal",
Done: false,
Priority: 4,
Description: "Learn Cloud Datastore",
})
return err
})
// [END datastore_transactional_get_or_create]
_ = err // Check error.
}
func SnippetTransaction_runQuery() {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
// [START datastore_transactional_single_entity_group_read_only]
tx, err := client.NewTransaction(ctx, datastore.ReadOnly)
if err != nil {
log.Fatalf("client.NewTransaction: %v", err)
}
defer tx.Rollback() // Transaction only used for read.
ancestor := datastore.NameKey("TaskList", "default", nil)
query := datastore.NewQuery("Task").Ancestor(ancestor).Transaction(tx)
var tasks []Task
_, err = client.GetAll(ctx, query, &tasks)
// [END datastore_transactional_single_entity_group_read_only]
_ = err // Check error.
}
// [START datastore_namespace_run_query]
func metadataNamespaces(w io.Writer, projectID string) error {
// projectID := "my-project"
ctx := context.Background()
client, err := datastore.NewClient(ctx, projectID)
if err != nil {
return fmt.Errorf("datastore.NewClient: %w", err)
}
defer client.Close()
start := datastore.NameKey("__namespace__", "g", nil)
end := datastore.NameKey("__namespace__", "h", nil)
query := datastore.NewQuery("__namespace__").
FilterField("__key__", ">=", start).
FilterField("__key__", "<", end).
KeysOnly()
keys, err := client.GetAll(ctx, query, nil)
if err != nil {
return fmt.Errorf("client.GetAll: %w", err)
}
fmt.Fprintln(w, "Namespaces:")
for _, k := range keys {
fmt.Fprintf(w, "\t%v", k.Name)
}
return nil
}
// [END datastore_namespace_run_query]
func TestMetadaNamespaces(t *testing.T) {
tc := testutil.SystemTest(t)
buf := &bytes.Buffer{}
if err := metadataNamespaces(buf, tc.ProjectID); err != nil {
t.Errorf("metadataNamespaces got err: %v, want no error", err)
}
if got, want := buf.String(), "Namespaces"; !strings.Contains(got, want) {
t.Errorf("metadataNamespaces got\n----\n%v\n----\nWant to contain:\n----\n%v\n----", got, want)
}
}
func Snippet_metadataKinds() {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
// [START datastore_kind_run_query]
query := datastore.NewQuery("__kind__").KeysOnly()
keys, err := client.GetAll(ctx, query, nil)
if err != nil {
log.Fatalf("client.GetAll: %v", err)
}
kinds := make([]string, 0, len(keys))
for _, k := range keys {
kinds = append(kinds, k.Name)
}
// [END datastore_kind_run_query]
}
func Snippet_metadataProperties() {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
// [START datastore_property_run_query]
query := datastore.NewQuery("__property__").KeysOnly()
keys, err := client.GetAll(ctx, query, nil)
if err != nil {
log.Fatalf("client.GetAll: %v", err)
}
props := make(map[string][]string) // Map from kind to slice of properties.
for _, k := range keys {
prop := k.Name
kind := k.Parent.Name
props[kind] = append(props[kind], prop)
}
// [END datastore_property_run_query]
}
func Snippet_metadataPropertiesForKind() {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
// [START datastore_property_by_kind_run_query]
kindKey := datastore.NameKey("__kind__", "Task", nil)
query := datastore.NewQuery("__property__").Ancestor(kindKey)
type Prop struct {
Repr []string `datastore:"property_representation"`
}
var props []Prop
keys, err := client.GetAll(ctx, query, &props)
// [END datastore_property_by_kind_run_query]
_ = err // Check error.
_ = keys // Use keys to find property names, and props for their representations.
}
func SnippetQuery_RunQueryWithExplain(w io.Writer) {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
// [START datastore_query_explain_entity]
// Build the query
query := datastore.NewQuery("Task")
// Set the explain options to get back *only* the plan summary
it := client.RunWithOptions(ctx, query, datastore.ExplainOptions{})
_, err := it.Next(nil)
// Get the explain metrics
explainMetrics := it.ExplainMetrics
planSummary := explainMetrics.PlanSummary
fmt.Fprintln(w, "----- Indexes Used -----")
for k, v := range planSummary.IndexesUsed {
fmt.Fprintf(w, "%+v: %+v\n", k, v)
}
// [END datastore_query_explain_entity]
_ = err // Check non-nil errors other than Iterator.Done
}
func SnippetQuery_RunQueryWithExplainAnalyze(w io.Writer) {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
// [START datastore_query_explain_analyze_entity]
// Build the query
query := datastore.NewQuery("Task")
// Set explain options with analzye = true to get back the query stats, plan info, and query
// results
it := client.RunWithOptions(ctx, query, datastore.ExplainOptions{Analyze: true})
// Get the query results
fmt.Fprintln(w, "----- Query Results -----")
for {
var task Task
_, err := it.Next(&task)
if err == iterator.Done {
break
}
if err != nil {
fmt.Fprintf(w, "Error fetching next task: %v", err)
return
}
fmt.Fprintf(w, "Task %q, Priority %d\n", task.Description, task.Priority)
}
// Get plan summary
planSummary := it.ExplainMetrics.PlanSummary
fmt.Fprintln(w, "----- Indexes Used -----")
for k, v := range planSummary.IndexesUsed {
fmt.Fprintf(w, "%+v: %+v\n", k, v)
}
// Get the execution stats
executionStats := it.ExplainMetrics.ExecutionStats
fmt.Fprintln(w, "----- Execution Stats -----")
fmt.Fprintf(w, "%+v\n", executionStats)
fmt.Fprintln(w, "----- Debug Stats -----")
for k, v := range *executionStats.DebugStats {
fmt.Fprintf(w, "%+v: %+v\n", k, v)
}
// [END datastore_query_explain_analyze_entity]
}
func SnippetQuery_RunAggregationQueryWithExplain(w io.Writer) {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
// [START datastore_query_explain_aggregation]
// Build the query
query := datastore.NewQuery("Task")
// Set the explain options to get back *only* the plan summary
ar, err := client.RunAggregationQueryWithOptions(ctx, query.NewAggregationQuery().WithCount("count"), datastore.ExplainOptions{})
// Get the explain metrics
explainMetrics := ar.ExplainMetrics
planSummary := explainMetrics.PlanSummary
fmt.Fprintln(w, "----- Indexes Used -----")
for k, v := range planSummary.IndexesUsed {
fmt.Fprintf(w, "%+v: %+v\n", k, v)
}
// [END datastore_query_explain_aggregation]
_ = err // Check non-nil errors
}
func SnippetQuery_RunAggregationQueryWithExplainAnalyze(w io.Writer) {
ctx := context.Background()
client, _ := datastore.NewClient(ctx, "my-proj")
defer client.Close()
// [START datastore_query_explain_analyze_aggregation]
// Build the query
query := datastore.NewQuery("Task")
// Set explain options with analzye = true to get back the query stats, plan info, and query
// results
countAlias := "count"
ar, err := client.RunAggregationQueryWithOptions(ctx,
query.NewAggregationQuery().WithCount(countAlias), datastore.ExplainOptions{Analyze: true})
// Get the query results
fmt.Fprintln(w, "----- Query Results -----")
result := ar.Result[countAlias]
fmt.Fprintf(w, "Count %v\n", result)
// Get plan summary
planSummary := ar.ExplainMetrics.PlanSummary
fmt.Fprintln(w, "----- Indexes Used -----")
for k, v := range planSummary.IndexesUsed {
fmt.Fprintf(w, "%+v: %+v\n", k, v)
}
// Get the execution stats
executionStats := ar.ExplainMetrics.ExecutionStats
fmt.Fprintln(w, "----- Execution Stats -----")
fmt.Fprintf(w, "%+v\n", executionStats)
fmt.Fprintln(w, "----- Debug Stats -----")
for k, v := range *executionStats.DebugStats {
fmt.Fprintf(w, "%+v: %+v\n", k, v)
}
// [END datastore_query_explain_analyze_aggregation]
_ = err // Check non-nil errors
}