ODBC Driver for ClickHouse

Introduction

This is the official ODBC driver implementation for accessing ClickHouse as a data source.

For more information on ClickHouse go to ClickHouse home page.

For more information on what ODBC is go to ODBC Overview.

The canonical repo for this driver is located at https://github.com/ClickHouse/clickhouse-odbc.

See LICENSE file for licensing information.

Table of contents

• Installation
• Configuration
  • URL query string
  • Troubleshooting: driver manager tracing and driver logging
• Building from sources
• Appendices
  • Run-time dependencies: Windows
  • Run-time dependencies: macOS
  • Run-time dependencies: Red Hat/CentOS
  • Run-time dependencies: Debian/Ubuntu
  • Configuration: MDAC/WDAC (Microsoft/Windows Data Access Components)
  • Configuration: UnixODBC
  • Configuration: iODBC
  • Enabling driver manager tracing: MDAC/WDAC (Microsoft/Windows Data Access Components)
  • Enabling driver manager tracing: UnixODBC
  • Enabling driver manager tracing: iODBC
  • Building from sources: Windows
  • Building from sources: macOS
  • Building from sources: Red Hat/CentOS
  • Building from sources: Debian/Ubuntu

Installation

Pre-built binary packages of the release versions of the driver available for the most common platforms at:

• Releases

The ODBC driver is mainly tested against ClickHouse server version 21.3. Older versions of ClickHouse server as well as newer ones (with greater success) should work too. Possible complications with older version may include handling Null values and Nullable types, alternative wire protocol support, timezone handling during date/time conversions, etc.

Note, that since ODBC drivers are not used directly by a user, but rather accessed through applications, which in their turn access the driver through ODBC driver manager, user have to install the driver for the same architecture (32- or 64-bit) as the application that is going to access the driver. Moreover, both the driver and the application must be compiled for (and actually use during run-time) the same ODBC driver manager implementation (we call them "ODBC providers" here). There are three supported ODBC providers:

• ODBC driver manager associated with MDAC (Microsoft Data Access Components, sometimes referenced as WDAC, Windows Data Access Components) - the standard ODBC provider of Windows
• UnixODBC - the most common ODBC provider in Unix-like systems. Theoretically, could be used in Cygwin or MSYS/MinGW environments in Windows too.
• iODBC - less common ODBC provider, mainly used in Unix-like systems, however, it is the standard ODBC provider in macOS. Theoretically, could be used in Cygwin or MSYS/MinGW environments in Windows too.

If you have Homebrew installed (usually applicable to macOS only, but can also be available in Linux), just execute:

brew install clickhouse-odbc

If you don't see a package that matches your platforms under Releases, or the version of your system is significantly different than those of the available packages, or maybe you want to try a bleeding edge version of the code that hasn't been released yet, you can always build the driver manually from sources:

• Building from sources

Note, that it is always a good idea to install the driver from the corresponding native package (if one is supported for your platform, like .msi, etc., which you can also easily create if you are building from sources), than use the binaries that were manually copied to a destination folder.

Native packages will have all the dependency information so when you install the driver using a native package, all required run-time packages will be installed automatically. If you use manual packaging, i.e., just extract driver binaries to some folder, you also have to make sure that all the run-time dependencies are satisfied in your system manually:

• Run-time dependencies: Windows
• Run-time dependencies: macOS
• Run-time dependencies: Red Hat/CentOS
• Run-time dependencies: Debian/Ubuntu

Configuration

The first step usually consists of registering the driver so that the corresponding ODBC provider is able to locate it.

The next step is defining one or more DSNs, associated with the newly registered driver, and setting driver-specific parameters in the body of those DSN definitions.

All this involves modifying a dedicated registry keys in case of MDAC, or editing odbcinst.ini (for driver registration) and odbc.ini (for DSN definition) files for UnixODBC or iODBC, directly or indirectly.

This will be performed automatically using some default values if you are installing the driver using native installers.

Otherwise, if you are configuring manually, or need to modify the default configuration created by the installer, please see the exact locations of files (or registry keys) that need to be modified in the corresponding section below:

• Configuration: MDAC/WDAC (Microsoft/Windows Data Access Components)
• Configuration: UnixODBC
• Configuration: iODBC

The list of DSN parameters recognized by the driver is as follows:

URL query string

Some of configuration parameters can be passed to the server as a part of the query string of the URL.

The list of parameters in the query string of the URL that are also recognized by the driver is as follows:

Note, that currently there is a difference in timezone handling between ODBCDriver2 and RowBinaryWithNamesAndTypes formats: in ODBCDriver2 date and time values are presented to the ODBC application in server's timezone, wherease in RowBinaryWithNamesAndTypes they are converted to local timezone. This behavior will be changed/parametrized in future. If server and ODBC application timezones are the same, date and time values handling will effectively be identical between these two formats.

Troubleshooting: driver manager tracing and driver logging

To debug issues with the driver, first things that need to be done are:

• enabling driver manager tracing:
  • Enabling driver manager tracing: MDAC/WDAC (Microsoft/Windows Data Access Components)
  • Enabling driver manager tracing: UnixODBC
  • Enabling driver manager tracing: iODBC
• enabling driver logging, see DriverLog and DriverLogFile DSN parameters above
• making sure that the application is allowed to create and write these driver log and driver manager trace files

Building from sources

The general requirements for building the driver from sources are as follows:

• CMake 3.13.5 and later
• C++17 and C11 capable compiler toolchain:
  • Clang 4 and later
  • GCC 7 and later
  • Xcode 10 and later (on macOS 10.14 and later)
  • Microsoft Visual Studio 2017 and later

Additional requirements exist for each platform, which also depend on whether packaging and/or testing is performed.

See the exact steps for each platform in the corresponding section below:

• Building from sources: Windows
• Building from sources: macOS
• Building from sources: Red Hat/CentOS
• Building from sources: Debian/Ubuntu

The list of configuration options recognized during the CMake generation step is as follows:

Configuration options above can be specified in the first cmake command (generation step) in a form of -Dopt=val.

Appendices

Run-time dependencies: Windows

All modern Windows systems come with preinstalled MDAC driver manager.

Another run-time dependecies are C++ Redistributable for Visual Studio 2017 or same for 2019, etc., depending on the package being installed, however the required DLL's are redistributed with the .msi installer, and you can choose to install them from there, if you don't have them installed in your system already.

Run-time dependencies: macOS

iODBC

Execute the following in the terminal (assuming you have Homebrew installed):

brew update
brew install poco openssl icu4c libiodbc

UnixODBC

Execute the following in the terminal (assuming you have Homebrew installed):

brew update
brew install poco openssl icu4c unixodbc

Run-time dependencies: Red Hat/CentOS

UnixODBC

Execute the following in the terminal:

sudo yum install openssl libicu unixODBC

iODBC

Execute the following in the terminal:

sudo yum install openssl libicu libiodbc

Run-time dependencies: Debian/Ubuntu

UnixODBC

Execute the following in the terminal:

sudo apt install openssl libicu unixodbc

iODBC

Execute the following in the terminal:

sudo apt install openssl libicu libiodbc2

Configuration: MDAC/WDAC (Microsoft/Windows Data Access Components)

To configure already installed drivers and DSNs, or create new DSNs, use Microsoft ODBC Data Source Administrator tool:

• for 32-bit applications (and drivers) execute %systemdrive%\Windows\SysWoW64\Odbcad32.exe
• for 64-bit applications (and drivers) execute %systemdrive%\Windows\System32\Odbcad32.exe

For full description of ODBC configuration mechanism in Windows, as well as for the case when you want to learn how to manually register a driver and have a full control on configuration in general, see:

• Installing and Configuring the ODBC Software

Note, that the keys are subject to "Registry Redirection" mechanism, with caveats.

You can find sample configuration for this driver here (just map the keys to corresponding sections in registry):

• odbcinst.ini.sample
• odbc.ini.sample

Configuration: UnixODBC

In short, usually you will end up editing /etc/odbcinst.ini and /etc/odbc.ini for system-wide driver and DSN entries, and ~/.odbcinst.ini and ~/.odbc.ini for user-wide driver and DSN entries.

There can be exceptions to this, as these paths are configurable during the compilation of UnixODBC itself, or during the run-time via ODBCINI, ODBCINSTINI, and ODBCSYSINI.

For more info, see:

• unixODBC without the GUI
• odbcinst - An unixODBC tool for manipulating configuration files
• unixODBC - An ODBC implementation for Unix - for description of recognized run-time environment variables

You can find sample configuration for this driver here:

• odbcinst.ini.sample
• odbc.ini.sample

These samples can be added to the corresponding configuration files using the odbcinst tool (assuming the package is installed under /usr/local):

odbcinst -i -d -f /usr/local/share/doc/clickhouse-odbc/config/odbcinst.ini.sample
odbcinst -i -s -l -f /usr/local/share/doc/clickhouse-odbc/config/odbc.ini.sample

Configuration: iODBC

In short, usually you will end up editing /etc/odbcinst.ini and /etc/odbc.ini for system-wide driver and DSN entries, and ~/.odbcinst.ini and ~/.odbc.ini for user-wide driver and DSN entries.

In macOS, if those INI files exist, they usually are symbolic or hard links to /Library/ODBC/odbcinst.ini and /Library/ODBC/odbc.ini for system-wide, and ~/Library/ODBC/odbcinst.ini and ~/Library/ODBC/odbc.ini for user-wide configs respectively.

There can be exceptions to this, as these paths are configurable during the compilation of iODBC itself, or during the run-time via ODBCINI and ODBCINSTINI. Note, that ODBCINSTINI in iODBC contains the full path to the file, while for UnixODBC it is a file name, and the file itself is expected to be under ODBCSYSINI dir.

For more info, see:

• What's an odbc.ini and what do I put in it?
• What's a libiodbc and what goes in my Driver= lines in odbc.ini?

You can find sample configuration for this driver here:

• odbcinst.ini.sample
• odbc.ini.sample

Enabling driver manager tracing: MDAC/WDAC (Microsoft/Windows Data Access Components)

Comprehensive explanations (possibly, with some irrelevant vendor-specific details though) on how to enable ODBC driver manager tracing could be found at the following links:

• 5.8.1 Enabling ODBC Tracing on Windows
• ODBC Troubleshooting: How to Enable Driver-manager Tracing
• Enabling Tracing

Enabling driver manager tracing: UnixODBC

Comprehensive explanations (possibly, with some irrelevant vendor-specific details though) on how to enable ODBC driver manager tracing could be found at the following links:

• ODBC Troubleshooting: How to Enable Driver-manager Tracing
• How do I turn unixODBC tracing on or off?

Enabling driver manager tracing: iODBC

Comprehensive explanations (possibly, with some irrelevant vendor-specific details though) on how to enable ODBC driver manager tracing could be found at the following links:

• ODBC Troubleshooting: How to Enable Driver-manager Tracing
• Tracing Application Behavior

Building from sources: Windows

Build-time dependencies

CMake bundled with the recent versions of Visual Studio can be used.

An SDK required for building the ODBC driver is included in Windows SDK, which in its turn is also bundled with Visual Studio.

You will need to install WiX toolset to be able to generate .msi packages. You can download and install it from WiX toolset home page.

Build steps

All of the following commands have to be issued in Visual Studio Command Prompt:

• use x86 Native Tools Command Prompt for VS 2019 or equivalent for 32-bit builds
• use x64 Native Tools Command Prompt for VS 2019 or equivalent for 64-bit builds

Clone the repo with submodules:

git clone --recursive [email protected]:ClickHouse/clickhouse-odbc.git

Enter the cloned source tree, create a temporary build folder, and generate the solution and project files in it:

cd clickhouse-odbc
mkdir build
cd build

# Configuration options for the project can be specified in the next command in a form of '-Dopt=val'

# Use the following command for 32-bit build only.
cmake -A Win32 -DCMAKE_BUILD_TYPE=RelWithDebInfo ..

# Use the following command for 64-bit build only.
cmake -A x64 -DCMAKE_BUILD_TYPE=RelWithDebInfo ..

Build the generated solution in-place:

cmake --build . --config RelWithDebInfo
cmake --build . --config RelWithDebInfo --target package

...and, optionally, run tests (note, that for non-unit tests, preconfigured driver and DSN entries must exist, that point to the binaries generated in this build folder):

cmake --build . --config RelWithDebInfo --target test

...or open the IDE and build all, package, and test targets manually from there:

cmake --open .

Building from sources: macOS

Build-time dependencies

You will need macOS 10.14 or later, Xcode 10 or later with Command Line Tools installed, as well as up-to-date Homebrew available in the system.

Install Homebrew using the following command, and follow the printed instructions on any additional steps required to complete the installation:

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

Then, install the latest Xcode from App Store. Open it at least once to accept the end-user license agreement and automatically install the required components.

Then, make sure that the latest Command Line Tools are installed and selected in the system:

sudo rm -rf /Library/Developer/CommandLineTools
sudo xcode-select --install

Reboot.

Build-time dependencies: iODBC

Execute the following in the terminal:

brew update
brew install git cmake make poco openssl icu4c libiodbc

Build-time dependencies: UnixODBC

Execute the following in the terminal:

brew update
brew install git cmake make poco openssl icu4c unixodbc

Build steps

Clone the repo recursively with submodules:

git clone --recursive [email protected]:ClickHouse/clickhouse-odbc.git

Enter the cloned source tree, create a temporary build folder, and generate a Makefile for the project in it:

cd clickhouse-odbc
mkdir build
cd build

# Configuration options for the project can be specified in the next command in a form of '-Dopt=val'.

# You may also add '-G Xcode' to the next command, in order to use Xcode as a build system or IDE, and generate the solution and project files instead of Makefile.
cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo -DOPENSSL_ROOT_DIR=$(brew --prefix)/opt/openssl -DICU_ROOT=$(brew --prefix)/opt/icu4c ..

Build the generated solution in-place:

cmake --build . --config RelWithDebInfo
cmake --build . --config RelWithDebInfo --target package

...and, optionally, run tests (note, that for non-unit tests, preconfigured driver and DSN entries must exist, that point to the binaries generated in this build folder):

cmake --build . --config RelWithDebInfo --target run_tests

...or, if you configured the project with '-G Xcode' initially, open the IDE and build all, package, and run_tests targets manually from there:

cmake --open .

Building from sources: Red Hat/CentOS

Build-time dependencies: UnixODBC

Execute the following in the terminal:

sudo yum install epel-release
sudo yum groupinstall "Development Tools"
sudo yum install centos-release-scl
sudo yum install devtoolset-8
sudo yum install git cmake3 rpm-build openssl-devel libicu-devel unixODBC-devel

Build-time dependencies: iODBC

Execute the following in the terminal:

sudo yum install epel-release
sudo yum groupinstall "Development Tools"
sudo yum install centos-release-scl
sudo yum install devtoolset-8
sudo yum install git cmake3 rpm-build openssl-devel libicu-devel libiodbc-devel

Build steps

All of the following commands have to be issued right after this one command issued in the same terminal session:

scl enable devtoolset-8 -- bash

Clone the repo with submodules:

git clone --recursive [email protected]:ClickHouse/clickhouse-odbc.git

Enter the cloned source tree, create a temporary build folder, and generate a Makefile for the project in it:

cd clickhouse-odbc
mkdir build
cd build

# Configuration options for the project can be specified in the next command in a form of '-Dopt=val'

cmake3 -DCMAKE_BUILD_TYPE=RelWithDebInfo ..

Build the generated solution in-place:

cmake3 --build . --config RelWithDebInfo
cmake3 --build . --config RelWithDebInfo --target package

...and, optionally, run tests (note, that for non-unit tests, preconfigured driver and DSN entries must exist, that point to the binaries generated in this build folder):

cmake3 --build . --config RelWithDebInfo --target test

Building from sources: Debian/Ubuntu

Build-time dependencies: UnixODBC

Execute the following in the terminal:

sudo apt install build-essential git cmake libpoco-dev libssl-dev libicu-dev unixodbc-dev

Build-time dependencies: iODBC

Execute the following in the terminal:

sudo apt install build-essential git cmake libpoco-dev libssl-dev libicu-dev libiodbc2-dev

Build steps

Assuming, that the system cc and c++ are pointing to the compilers that satisfy the minimum requirements from Building from sources.

If the version of cmake is not recent enough, you can install a newer version by folowing instructions from one of these pages:

• Kitware APT Repository
• Installing CMake

Clone the repo with submodules:

git clone --recursive [email protected]:ClickHouse/clickhouse-odbc.git

Enter the cloned source tree, create a temporary build folder, and generate a Makefile for the project in it:

cd clickhouse-odbc
mkdir build
cd build

# Configuration options for the project can be specified in the next command in a form of '-Dopt=val'

cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo ..

Build the generated solution in-place:

cmake --build . --config RelWithDebInfo
cmake --build . --config RelWithDebInfo --target package

...and, optionally, run tests (note, that for non-unit tests, preconfigured driver and DSN entries must exist, that point to the binaries generated in this build folder):

cmake --build . --config RelWithDebInfo --target test