Access BigQuery with service account (golang).

accessBigquery.go

//This is sample source code.
package main

import (
	"cloud.google.com/go/bigquery"
	"fmt"
	"golang.org/x/net/context"
	"golang.org/x/oauth2/google"
	bq "google.golang.org/api/bigquery/v2"
	"google.golang.org/api/iterator"
	"google.golang.org/api/option"
	"os"
)

func main() {
	json := os.Getenv("GOOGLE_APPLICATION_CREDENTIALS")
	ctx := context.Background()
	projectID := os.Getenv("BQ_ID")
	jwtConfig, err := google.JWTConfigFromJSON([]byte(json), bq.BigqueryScope)
	if err != nil {
		fmt.Printf("Json load error: %v\n", err)
	}
	ts := jwtConfig.TokenSource(ctx)
	client, err := bigquery.NewClient(ctx, projectID, option.WithTokenSource(ts))
	if err != nil {
		fmt.Printf("Client create error: %v\n", err)
	}

	bqSql := " SELECT zipp.zip as zip, zipp.address as address FROM [zip.zip] zipp WHERE RAND() < 100/123920 limit 109 "
	fmt.Println(bqSql)

	q := client.Query(bqSql)
	it, err := q.Read(ctx)
	if err != nil {
		fmt.Printf("Error2: %v\n", err)
	}
	for {
		var values []bigquery.Value
		err := it.Next(&values)
		if err == iterator.Done {
			break
		}
		if err != nil {
			fmt.Printf("Error3: %v\n", err)
		}
		fmt.Printf(values[0].(string))
		fmt.Printf(values[1].(string))
	}
}

I wrote this code for use bigquery from heroku.
If you want to know how to set up GCP and Heroku, read my blog.
However, this blog is written with Japanese... sorry.