Google Cloud BigQuery C++ Client  2.2.1
A C++ Client Library for Google Cloud BigQuery
Cloud BigQuery C++ Client Library

The Cloud BigQuery C++ Client library offers types and functions to use Cloud BigQuery from C++11 applications.

This library requires a C++14 compiler. It is supported (and tested) on multiple Linux distributions, macOS, and Windows.


The following instructions show you how to perform basic tasks in Cloud BigQuery using the C++ client library.

Before you begin

  1. Select or create a Google Cloud Platform (GCP) project using the manage resource page. Make a note of the project id as you will need to use it later.
  2. Make sure that billing is enabled for your project.
  3. Learn about key terms and concepts for Cloud BigQuery.
  4. Setup the authentication for the examples:
    • [Configure a service account][gcloud-authorizing],
    • or [login with your personal account][gcloud-authorizing]

Setting up your repo

In order to use the Cloud BigQuery C++ client library from your own code, you'll need to configure your build system to fetch and compile the Cloud C++ client library. The Cloud BigQuery C++ client library natively supports the Bazel and CMake build systems. We've created a minimal, "Hello world", quickstart repo that includes detailed instructions on how to compile the library for use in your application. You can fetch the source from GitHub as normal:

git clone
cd google-cloud-cpp/google/cloud/bigquery/quickstart
Example: Hello World

The following shows the code that you'll run in the google/cloud/bigquery/quickstart/ directory, which should give you a taste of the Cloud BigQuery C++ client library API.

// Copyright 2021 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
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.
#include <iostream>
#include <stdexcept>
namespace {
void ProcessRowsInAvroFormat(
::google::cloud::bigquery::storage::v1::AvroSchema const&,
::google::cloud::bigquery::storage::v1::AvroRows const&) {
// Code to deserialize avro rows should be added here.
} // namespace
int main(int argc, char* argv[]) try {
if (argc != 3) {
std::cerr << "Usage: " << argv[0] << " <project-id> <table-name>\n";
return 1;
// project_name should be in the format "projects/<your-gcp-project>"
std::string const project_name = "projects/" + std::string(argv[1]);
// table_name should be in the format:
// "projects/<project-table-resides-in>/datasets/<dataset-table_resides-in>/tables/<table
// name>" The project values in project_name and table_name do not have to be
// identical.
std::string const table_name = argv[2];
// Create a namespace alias to make the code easier to read.
namespace bigquery = ::google::cloud::bigquery;
constexpr int kMaxReadStreams = 1;
// Create the ReadSession.
auto client =
::google::cloud::bigquery::storage::v1::ReadSession read_session;
auto session =
client.CreateReadSession(project_name, read_session, kMaxReadStreams);
if (!session) throw std::runtime_error(session.status().message());
// Read rows from the ReadSession.
constexpr int kRowOffset = 0;
auto read_rows = client.ReadRows(session->streams(0).name(), kRowOffset);
std::int64_t num_rows = 0;
for (auto const& row : read_rows) {
if (row.ok()) {
num_rows += row->row_count();
ProcessRowsInAvroFormat(session->avro_schema(), row->avro_rows());
std::cout << num_rows << " rows read from table: " << table_name << "\n";
return 0;
} catch (std::exception const& ex) {
std::cerr << "Standard exception raised: " << ex.what() << "\n";
return 1;
std::shared_ptr< BigQueryReadConnection > MakeBigQueryReadConnection(Options options={})
A factory function to construct an object of type BigQueryReadConnection.

API Notes

The following are general notes about using the library.

Environment Variables

There are several environment variables that can be set to configure certain behaviors in the library.

  • GOOGLE_CLOUD_CPP_BIGQUERY_READ_ENDPOINT=... changes the default endpoint ( used by BigQueryReadConnection.
  • GOOGLE_CLOUD_CPP_BIGQUERY_WRITE_ENDPOINT=... changes the default endpoint ( used by BigQueryWriteConnection.
  • GOOGLE_CLOUD_CPP_BIGQUERY_CONNECTION_SERVICE_ENDPOINT=... changes the default endpoint ( used by ConnectionServiceConnection.
  • GOOGLE_CLOUD_CPP_DATA_TRANSFER_SERVICE_ENDPOINT=... changes the default endpoint ( used by DataTransferServiceConnection.
  • GOOGLE_CLOUD_CPP_MODEL_SERVICE_ENDPOINT=... changes the default endpoint ( used by ModelServiceConnection.
  • GOOGLE_CLOUD_CPP_RESERVATION_SERVICE_ENDPOINT=... changes the default endpoint ( used by ReservationServiceConnection.
  • GOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc turns on tracing for most gRPC calls. The library injects an additional Stub decorator that prints each gRPC request and response. Unless you have configured you own logging backend, you should also set GOOGLE_CLOUD_CPP_ENABLE_CLOG to produce any output on the program's console.
  • GOOGLE_CLOUD_CPP_TRACING_OPTIONS=... modifies the behavior of gRPC tracing, including whether messages will be output on multiple lines, or whether string/bytes fields will be truncated.
  • GOOGLE_CLOUD_PROJECT=... is used in examples and integration tests to configure the GCP project.
  • GOOGLE_CLOUD_CPP_ENABLE_CLOG=yes turns on logging in the library, basically the library always "logs" but the logging infrastructure has no backend to actually print anything until the application sets a backend or they set this environment variable.

Error Handling

This library never throws exceptions to signal errors. In general, the library returns a StatusOr<T> if an error is possible. Some functions return objects that are not wrapped in a StatusOr<> but will themselves return a StatusOr<T> to signal an error. For example, wrappers for asynchronous operations return future<StatusOr<T>>.

Applications should check if the StatusOr<T> contains a value before using it, much like how you might check that a pointer is not null before dereferencing it. Indeed, a StatusOr<T> object can be used like a smart-pointer to T, with the main difference being that when it does not hold a T it will instead hold a Status object with extra information about the error.

You can check that a StatusOr<T> contains a value by calling the .ok() method, or by using operator bool() (like with other smart pointers). If there is no value, you can access the contained Status object using the .status() member. If there is a value, you may access it by dereferencing with operator*() or operator->(). As with all smart pointers, callers must first check that the StatusOr<T> contains a value before dereferencing and accessing the contained value. Alternatively, callers may instead use the .value() member function which is defined to throw a RuntimeStatusError if there is no value.

If you're compiling with exceptions disabled, calling .value() on a StatusOr<T> that does not contain a value will terminate the program instead of throwing.
namespace bigquery = ::google::cloud::bigquery;
[](std::string const& project_id, std::string const& table_name) {
int max_stream_count = 1;
google::cloud::bigquery::storage::v1::ReadSession read_session;
bigquery::BigQueryReadClient client(bigquery::MakeBigQueryReadConnection());
// The actual type of `session` is
// google::cloud::StatusOr<google::cloud::bigquery::storage::v1::ReadSession>,
// but we expect it'll most often be declared with auto like this.
auto session = client.CreateReadSession("projects/" + project_id,
read_session, max_stream_count);
if (!session) {
std::cerr << session.status() << "\n";
std::cout << "ReadSession successfully created: " << session->name()
<< ".\n";

Next Steps

Testing your Cloud BigQueryRead application with googlemock