ClickHouse C++ client – Connecting to ClickHouse with C++ client libraries

ClickHouse C++ client is a client library for C++ development allowing applications to connect to ClickHouse databases based on the clickhouse-native-client library. The library was originally developed by the ClickHouse core community development teams and we at ChistaDATA maintain the fork for the same on GitHub.

Supported data types

• Array(T)
• Date
• DateTime, DateTime64
• DateTime([timezone]), DateTime64(N, [timezone])
• Decimal32, Decimal64, Decimal128
• Enum8, Enum16
• FixedString(N)
• Float32, Float64
• IPv4, IPv6
• Nullable(T)
• String
• LowCardinality(String) or LowCardinality(FixedString(N))
• Tuple
• UInt8, UInt16, UInt32, UInt64, Int8, Int16, Int32, Int64
• Int128
• UUID

How to build ClickHouse C++ client ?

$ mkdir build .
$ cd build
$ cmake .. [-DBUILD_TESTS=ON]
$ make

Test program on how to use ClickHouse C++ client

#include <clickhouse/client.h>

using namespace clickhouse;

/// Initialize client connection.
Client client(ClientOptions().SetHost("localhost"));

/// Create a table.
client.Execute("CREATE TABLE IF NOT EXISTS test.numbers (id UInt64, name String) ENGINE = Memory");

/// Insert some values.
{
    Block block;

    auto id = std::make_shared<ColumnUInt64>();
    id->Append(1);
    id->Append(7);

    auto name = std::make_shared<ColumnString>();
    name->Append("one");
    name->Append("seven");

    block.AppendColumn("id"  , id);
    block.AppendColumn("name", name);

    client.Insert("test.numbers", block);
}

/// Select values inserted in the previous step.
client.Select("SELECT id, name FROM test.numbers", [] (const Block& block)
    {
        for (size_t i = 0; i < block.GetRowCount(); ++i) {
            std::cout << block[0]->As<ColumnUInt64>()->At(i) << " "
                      << block[1]->As<ColumnString>()->At(i) << "\n";
        }
    }
);

/// Delete table.
client.Execute("DROP TABLE test.numbers");