cx_Oracle version 8.1

About cx_Oracle

cx_Oracle is a Python extension module that enables access to Oracle Database. It conforms to the Python database API 2.0 specification with a considerable number of additions and a couple of exclusions.

cx_Oracle 8 has been tested with Python versions 3.6 through 3.9. Older versions of cx_Oracle may be used with previous Python releases. You can use cx_Oracle with Oracle 11.2, 12, 18, 19 and 21 client libraries. Oracle’s standard client-server version interoperability allows connection to both older and newer databases. For example Oracle 19c client libraries can connect to Oracle Database 11.2.

Getting Started

Installation

Documentation

Tutorial

Samples

Issues and questions can be raised with the cx_Oracle community on GitHub or on the mailing list.

Tests

Contributing

Features

Easily installed from PyPI.

Support for Python 3.6 and higher. Older versions of cx_Oracle may be used with previous Python releases.

Support for Oracle Client 11.2, 12, 18, 19 and 21. Oracle’s standard cross-version interoperability, allows easy upgrades and connectivity to different Oracle Database versions.

Connect to Oracle Database 9.2, 10, 11, 12, 18, 19 or 21 (depending on the Oracle Client version used).

SQL and PL/SQL Execution. The underlying Oracle Client libraries have significant optimizations including compressed fetch, pre-fetching, client and server result set caching, and statement caching with auto-tuning.

Full use of Oracle Network Service infrastructure, including encrypted network traffic and security features.

Extensive Oracle data type support, including large object support (CLOB and BLOB).

Direct binding to SQL objects. One great use case is binding Python objects to Oracle Spatial SDO objects.

JSON datatype support.

SODA (Simple Oracle Document Access).

Array operations for efficient INSERT and UPDATEs.

Array row counts and batch error handling for array operations.

Fetching of large result sets.

REF CURSOR support.

Support for scrollable cursors. Go back and forth through your query results.

Fetch PL/SQL Implicit Results. Easily return query results from PL/SQL.

Row Prefetching. Efficient use of the network.

Client Result Caching. Improve performance of frequently executed look-up statements.

Support for Advanced Queuing. Use database notifications to build micro-service applications.

Continuous Query Notification (CQN). Get notified when data changes.

Support for Edition Based Redefinition. Easily switch applications to use updated PL/SQL logic.

Support for setting application context during the creation of a connection, making application metadata more accessible to the database, including in LOGON triggers.

End-to-end monitoring and tracing.

Session Pooling, with tagging and session state fix-up callback.

Database Resident Connection Pooling (DRCP).

Database startup and shutdown.

Oracle Database High Availability Features, such as FAN notifications, Application Continuity, and Transaction Guard support.

DB API specification exclusions: The time data type is not supported by Oracle and is therefore not implemented. The method cursor.nextset() is not implemented either as the DB API specification assumes an implementation of cursors that does not fit well with Oracle’s implementation of cursors and implicit results. See the method cursor.getimplicitresults() for more information.

License

cx_Oracle is licensed under a BSD license which you can find here. The cx_Oracle project is open source and maintained by Oracle Corp.

easy_install cx_Oracle (python package) on Windows

So I found Help installing cx_Oracle but am still stuck. I downloaded the latest instantclient from oracle, and set ORACLE_HOME to the location of the extracted files (both direct and with a bin folder between the ORACLE_HOME value and the files), but easy_install is popping an error when running setup.py saying it can’t locate the Oracle include files. I did notice that only the 11g dll is in the folder, do I need all 3 drivers present for setup to complete? If so, where do I even get them?

4 Answers 4

Honestly it is a hell of a lot easier to install cx_Oracle from one of the binary installers they have, than from source.

HOWTO for *nix:

Download the latest version of basic, sqlplus and sdk packages that fit your architecture (32 or 64bits):

Install the RPMs using alien. For example, at the time of this writing:

Add necessary environment variables (I personally did put it in /etc/environment then logoff/back in to reload the env):

Create /etc/ld.so.conf.d/oracle-instantclient -basic.conf and /etc/ld.so.conf.d/oracle.conf (for more recent versions, at least since 12.1) containing:

Reload ldconfig cache (use -v flag if you want some verbose):

You might need to install libaio1 .

HOWTO Install cx_Oracle

Assuming we have installed Oracle Instant Client 10, you have different alternatives to install cx_Oracle:

1. Install with pip: $ pip install cx_oracle (linux only)
2. Download the installer/.tar.gz file from the cx_oracle PyPI site

Older versions (version less than 5.1.2 are .msi and .rpm files) can be downloaded from here. Install the RPMs using alien. For example, at the time of this writing: $ sudo alien -i cx_Oracle-5.0-10g-py25-1.x86.rpm

To test, python -c ‘import cx_Oracle; print cx_Oracle’ should return the modules with its version.

step 1 check python is 32 bit or 64

or step 2 install oracle client (32 bit or 64 bit depends on python version from step1)

• download the oracle client from http://www.oracle.com/technetwork/database/enterprise-edition/downloads/112010-win32soft-098987.html(link for32 bit version) download and extract the zip files in one folder
• the zip files are extracted to ‘installation’ in this case

the directory will appear like this

click on install and set the path to ‘base’ and ‘software’ directories

software directory should be inside base directory(recommended)

in this case ‘installed’ directory is base and ‘software’ directory is for software path

set ORACLE_HOME path:

set the oracle home path to the ‘software’ directory as ‘F:\softwares\oracle11g32\installed\software’

in cmd check ‘echo %ORACLE_HOME%’ to see if the path is set properly

step 3 install vcforpython27 or visual c++ 2008 express edition for python 2.7

download it from here https://www.microsoft.com/en-sa/download/details.aspx?id=44266 (used this in this case to avoid installation of whole visual c++ 2008 as mentioned in below)

it is a small package that contains c++ compilers for python 2.7

visual c++ 2008 express edition ( https://www.microsoft.com/en-sa/download/details.aspx?id=5582 ) [it will around a 1 GB installation]

vcforpython27 will installed at ‘C:\Users\Administrator\AppData\Local\Programs\Common\Microsoft’

enable show hidden folder in windows to this these directories

it should point to the point to the directory containing ‘vcvarsall’ batch file

echo %VS100COMNTOOL% to see if is pointing to the right directory in cmd

go to C:/Python27/lib/distutils the file msvc9compiler.py. Find in it the function find_vcvarsall and do following modification. Replace the line: productdir = os.path.join(toolsdir, os.pardir, os.pardir, «VC») with productdir = os.path.join(toolsdir) This is where vcvarsall.bat resides in this case (check, where vcvarsall.bat is in your installation).

install cx_Oracle

if all the above steps are followed properly, then it should work. It took lot of pain to figure this out. I hope it will be useful.

recommended to run:

1. Download oracle instant client (for 32bit or 64bit archtitect and appropriate version of Oracle (10g,11g,12g)). http://www.oracle.com/technetwork/topics/winx64soft-089540.html

Note: Requires an user to authenticate with an OTN (oracle tech network account).

1.1. Download and unzip «Instant Client Package — Basic» to C:\Python27\Scripts\instantclient_11_2 e.g. instantclient-basic-windows.x64-11.2.0.4.0.zip

1.2. Download and unzip «Instant Client Package — SDK» to C:\Python27\Scripts\instantclient_11_2 e.g. instantclient-sdk-windows.x64-11.2.0.4.0.zip

python -m pip install cx_Oracle

Output on success: Collecting cx_Oracle Using cached cx_Oracle-5.2.1.tar.gz Building wheels for collected packages: cx-Oracle Running setup.py bdist_wheel for cx-Oracle . done Stored in directory: C:\Users\m315468\AppData\Local\pip\Cache\wheels\7c\5f\96\ cd273c9b675bc7c28ae249b74d1f7df5d3eacba9e918715225 Successfully built cx-Oracle Installing collected packages: cx-Oracle Successfully installed cx-Oracle-5.2.1

After struggling I found below method. I am using Windows and have separate environment for django.

1. Follow this link and go to Windows section. Now under Oracle «Instant Client Zip» you will see first step to download zip file depending on which version and bit you need. Download zip file.Remember django 2 dont support Oracle 11.
2. On Windows create below folder structure c:\oracle\instantclient_12_2
3. unzip your files under this folder.
4. Set the PATH in Control Panel -> System -> Advanced System Settings -> Advanced -> Environment Variables -> System Variables -> PATH. The Instant Client directory must come in PATH before any other Oracle directories.
5. Open other command prompt or restart current one.
6. conda activate
7. type python

run all below command one by one to test connection, mind the indentation at the last for loop.

cx_Oracle 8 Installation¶

Overview¶

To use cx_Oracle 8 with Python and Oracle Database you need:

• Python 3.5 and higher. Older versions of cx_Oracle may work with older versions of Python.
• Oracle Client libraries. These can be from the free Oracle Instant Client, or those included in Oracle Database if Python is on the same machine as the database. Oracle client libraries versions 19, 18, 12, and 11.2 are supported on Linux, Windows and macOS. Users have also reported success with other platforms. Use the latest client possible: Oracle’s standard client-server version interoperability allows connection to both older and newer databases.
• An Oracle Database, either local or remote.

The cx_Oracle module loads Oracle Client libraries which communicate over Oracle Net to an existing database. Oracle Net is not a separate product: it is how the Oracle Client and Oracle Database communicate.

Fig. 2 cx_Oracle Architecture

Quick Start cx_Oracle Installation¶

Install Python 3, if not already available. On macOS you must always install your own Python.

Python 3.5 and higher are supported by cx_Oracle 8. If you use Python 2, then the older cx_Oracle 7.3 will install.

Install cx_Oracle from PyPI with:

Note: if a binary wheel package is not available for your platform, the source package will be downloaded instead. This will be compiled and the resulting binary installed.

The —user option may be useful, if you don’t have permission to write to system directories:

If you are behind a proxy, add a proxy server to the command, for example add —proxy=http://proxy.example.com:80

Add Oracle 19, 18, 12 or 11.2 client libraries to your operating system library search path such as PATH on Windows or LD_LIBRARY_PATH on Linux. On macOS use init_oracle_client() in your application to pass the Oracle Client directory name, see Locating the Oracle Client Libraries . This is also usable on Windows.

To get the libraries:

If your database is on a remote computer, then download and unzip the client libraries from the free Oracle Instant Client “Basic” or “Basic Light” package for your operating system architecture.

Instant Client on Windows requires an appropriate Microsoft Windows Redistributables, see Installing cx_Oracle on Windows . On Linux, the libaio (sometimes called libaio1 ) package is needed. Oracle Linux 8 also needs the libnsl package.

Alternatively, use the client libraries already available in a locally installed database such as the free Oracle Database Express Edition (“XE”) release.

Version 19, 18 and 12.2 client libraries can connect to Oracle Database 11.2 or greater. Version 12.1 client libraries can connect to Oracle Database 10.2 or greater. Version 11.2 client libraries can connect to Oracle Database 9.2 or greater.

Create a script like the one below:

Locate your Oracle Database username and password, and the database connection string. The connection string is commonly of the format hostname/servicename , using the hostname where the database is running, and using the service name of the Oracle Database instance.

Substitute your username, password and connection string in the code. Run the Python script, for example:

You can learn how to use cx_Oracle from the API documentation and samples.

If you run into installation trouble, check out the section on Troubleshooting.

Oracle Client and Oracle Database Interoperability¶

cx_Oracle requires Oracle Client libraries. The libraries provide the necessary network connectivity to access an Oracle Database instance. They also provide basic and advanced connection management and data features to cx_Oracle.

The simplest way to get Oracle Client libraries is to install the free Oracle Instant Client “Basic” or “Basic Light” package. The libraries are also available in any Oracle Database installation or full Oracle Client installation.

Oracle’s standard client-server network interoperability allows connections between different versions of Oracle Client libraries and Oracle Database. For certified configurations see Oracle Support’s Doc ID 207303.1. In summary, Oracle Client 19, 18 and 12.2 can connect to Oracle Database 11.2 or greater. Oracle Client 12.1 can connect to Oracle Database 10.2 or greater. Oracle Client 11.2 can connect to Oracle Database 9.2 or greater. The technical restrictions on creating connections may be more flexible. For example Oracle Client 12.2 can successfully connect to Oracle Database 10.2.

cx_Oracle uses the shared library loading mechanism available on each supported platform to load the Oracle Client libraries at runtime. It does not need to be rebuilt for different versions of the libraries. Since a single cx_Oracle binary can use different client versions and also access multiple database versions, it is important your application is tested in your intended release environments. Newer Oracle clients support new features, such as the oraaccess.xml external configuration file available with 12.1 or later clients, session pool improvements, improved high availability features, call timeouts, and other enhancements.

The cx_Oracle function clientversion() can be used to determine which Oracle Client version is in use and the attribute Connection.version can be used to determine which Oracle Database version a connection is accessing. These can then be used to adjust application behavior accordingly. Attempts to use some Oracle features that are not supported by a particular client/server combination may result in runtime errors. These include:

• when attempting to access attributes that are not supported by the current Oracle Client library you will get the error “ORA-24315: illegal attribute type”
• when attempting to use implicit results with Oracle Client 11.2 against Oracle Database 12c you will get the error “ORA-29481: Implicit results cannot be returned to client”
• when attempting to get array DML row counts with Oracle Client 11.2 you will get the error “DPI-1050: Oracle Client library must be at version 12.1 or higher”

Installing cx_Oracle on Linux¶

This section discusses the generic installation methods on Linux. To use Python and cx_Oracle RPM packages from yum on Oracle Linux, see Installing cx_Oracle RPMs on Oracle Linux .

Install cx_Oracle¶

The generic way to install cx_Oracle on Linux is to use Python’s Pip package to install cx_Oracle from PyPI:

The —user option may be useful, if you don’t have permission to write to system directories:

If you are behind a proxy, add a proxy server to the command, for example add —proxy=http://proxy.example.com:80

This will download and install a pre-compiled binary if one is available for your architecture. If a pre-compiled binary is not available, the source will be downloaded, compiled, and the resulting binary installed. Compiling cx_Oracle requires the Python.h header file. If you are using the default python package, this file is in the python-devel package or equivalent.

Install Oracle Client¶

Using cx_Oracle requires Oracle Client libraries to be installed. These provide the necessary network connectivity allowing cx_Oracle to access an Oracle Database instance.

• If your database is on a remote computer, then download the free Oracle Instant Client “Basic” or “Basic Light” package for your operating system architecture. Use the RPM or ZIP packages, based on your preferences.
• Alternatively, use the client libraries already available in a locally installed database such as the free Oracle Database Express Edition (“XE”) release.

Oracle Instant Client Zip Files¶

To use cx_Oracle with Oracle Instant Client zip files:

Download an Oracle 19, 18, 12, or 11.2 “Basic” or “Basic Light” zip file: 64-bit or 32-bit, matching your Python architecture.

The latest version is recommended. Oracle Instant Client 19 will connect to Oracle Database 11.2 or later.

Unzip the package into a single directory that is accessible to your application. For example:

Install the libaio package with sudo or as the root user. For example:

On some Linux distributions this package is called libaio1 instead.

On recent Linux versions, such as Oracle Linux 8, you may also need to install the libnsl package.

If there is no other Oracle software on the machine that will be impacted, permanently add Instant Client to the runtime link path. For example, with sudo or as the root user:

Alternatively, set the environment variable LD_LIBRARY_PATH to the appropriate directory for the Instant Client version. For example:

If you use optional Oracle configuration files such as tnsnames.ora , sqlnet.ora or oraaccess.xml with Instant Client, then put the files in an accessible directory, for example in /opt/oracle/your_config_dir . Then use:

Or set the environment variable TNS_ADMIN to that directory name.

Alternatively, put the files in the network/admin subdirectory of Instant Client, for example in /opt/oracle/instantclient_19_9/network/admin . This is the default Oracle configuration directory for executables linked with this Instant Client.

Oracle Instant Client RPMs¶

To use cx_Oracle with Oracle Instant Client RPMs:

Download an Oracle 19, 18, 12, or 11.2 “Basic” or “Basic Light” RPM: 64-bit or 32-bit, matching your Python architecture.

The latest version is recommended. Oracle Instant Client 19 will connect to Oracle Database 11.2 or later.

Install the downloaded RPM with sudo or as the root user. For example:

Yum will automatically install required dependencies, such as libaio .

On recent Linux versions, such as Oracle Linux 8, you may need to manually install the libnsl package.

For Instant Client 19, the system library search path is automatically configured during installation.

For older versions, if there is no other Oracle software on the machine that will be impacted, permanently add Instant Client to the runtime link path. For example, with sudo or as the root user:

Alternatively, for version 18 and earlier, every shell running Python will need to have the environment variable LD_LIBRARY_PATH set to the appropriate directory for the Instant Client version. For example:

If you use optional Oracle configuration files such as tnsnames.ora , sqlnet.ora or oraaccess.xml with Instant Client, then put the files in an accessible directory, for example in /opt/oracle/your_config_dir . Then use:

Or set the environment variable TNS_ADMIN to that directory name.

Alternatively, put the files in the network/admin subdirectory of Instant Client, for example in /usr/lib/oracle/19.9/client64/lib/network/admin . This is the default Oracle configuration directory for executables linked with this Instant Client.

Local Database or Full Oracle Client¶

cx_Oracle applications can use Oracle Client 19, 18, 12, or 11.2 libraries from a local Oracle Database or full Oracle Client installation.

The libraries must be either 32-bit or 64-bit, matching your Python architecture.

Set required Oracle environment variables by running the Oracle environment script. For example:

For Oracle Database Express Edition (“XE”) 11.2, run:

Optional Oracle configuration files such as tnsnames.ora , sqlnet.ora or oraaccess.xml can be placed in $ORACLE_HOME/network/admin .

Alternatively, Oracle configuration files can be put in another, accessible directory. Then set the environment variable TNS_ADMIN to that directory name.

Installing cx_Oracle RPMs on Oracle Linux¶

Python and cx_Oracle RPM packages are available from the Oracle Linux yum server. Various versions of Python are easily installed. Using the yum server makes it easy to keep up to date.

Installing cx_Oracle on Windows¶

Install cx_Oracle¶

Use Python’s Pip package to install cx_Oracle from PyPI:

If you are behind a proxy, specify your proxy server:

This will download and install a pre-compiled binary if one is available for your architecture. If a pre-compiled binary is not available, the source will be downloaded, compiled, and the resulting binary installed.

Install Oracle Client¶

Using cx_Oracle requires Oracle Client libraries to be installed. These provide the necessary network connectivity allowing cx_Oracle to access an Oracle Database instance. Oracle Client versions 19, 18, 12 and 11.2 are supported.

• If your database is on a remote computer, then download the free Oracle Instant Client “Basic” or “Basic Light” package for your operating system architecture.
• Alternatively, use the client libraries already available in a locally installed database such as the free Oracle Database Express Edition (“XE”) release.

Oracle Instant Client Zip Files¶

To use cx_Oracle with Oracle Instant Client zip files:

Download an Oracle 19, 18, 12, or 11.2 “Basic” or “Basic Light” zip file: 64-bit or 32-bit, matching your Python architecture.

The latest version is recommended. Oracle Instant Client 19 will connect to Oracle Database 11.2 or later.

Windows 7 users: Note that Oracle 19c is not supported on Windows 7.

Unzip the package into a directory that is accessible to your application. For example unzip instantclient-basic-windows.x64-19.9.0.0.0dbru.zip to C:\oracle\instantclient_19_9 .

Oracle Instant Client libraries require a Visual Studio redistributable with a 64-bit or 32-bit architecture to match Instant Client’s architecture. Each Instant Client version requires a different redistributable version:

• For Instant Client 19 install VS 2017.
• For Instant Client 18 or 12.2 install VS 2013
• For Instant Client 12.1 install VS 2010
• For Instant Client 11.2 install VS 2005 64-bit or VS 2005 32-bit

Configure Oracle Instant Client¶

There are several alternative ways to tell cx_Oracle where your Oracle Client libraries are, see cx_Oracle 8 Initialization .

With Oracle Instant Client you can use init_oracle_client() in your application, for example:

Note a ‘raw’ string is used because backslashes occur in the path.

Alternatively, add the Oracle Instant Client directory to the PATH environment variable. The directory must occur in PATH before any other Oracle directories. Restart any open command prompt windows.

Another way to set PATH is to use a batch file that sets it before Python is executed, for example:

Invoke this batch file every time you want to run Python.

If you use optional Oracle configuration files such as tnsnames.ora , sqlnet.ora or oraaccess.xml with Instant Client, then put the files in an accessible directory, for example in C:\oracle\your_config_dir . Then use:

Or set the environment variable TNS_ADMIN to that directory name.

Alternatively, put the files in a network\admin subdirectory of Instant Client, for example in C:\oracle\instantclient_19_9\network\admin . This is the default Oracle configuration directory for executables linked with this Instant Client.

Local Database or Full Oracle Client¶

cx_Oracle applications can use Oracle Client 19, 18, 12, or 11.2 libraries libraries from a local Oracle Database or full Oracle Client.

The Oracle libraries must be either 32-bit or 64-bit, matching your Python architecture.

Set the environment variable PATH to include the path that contains OCI.DLL , if it is not already set.

Restart any open command prompt windows.

Optional Oracle configuration files such as tnsnames.ora , sqlnet.ora or oraaccess.xml can be placed in the network\admin subdirectory of the Oracle Database software installation.

Alternatively, pass config_dir to init_oracle_client() as shown in the previous section, or set TNS_ADMIN to the directory name.

Installing cx_Oracle on macOS¶

Install Python¶

Make sure you are not using the bundled Python. This has restricted entitlements and will fail to load Oracle client libraries. Instead use Homebrew or Python.org.

Install cx_Oracle¶

Use Python’s Pip package to install cx_Oracle from PyPI:

The —user option may be useful, if you don’t have permission to write to system directories:

If you are behind a proxy, add a proxy server to the command, for example add —proxy=http://proxy.example.com:80

The source will be downloaded, compiled, and the resulting binary installed.

Install Oracle Instant Client¶

Oracle Instant Client provides the network connectivity for accessing Oracle Database.

Manual Installation¶

Download the Basic 64-bit DMG from Oracle.

In Finder, double click on the DMG to mount it.

Open a terminal window and run the install script in the mounted package, for example:

This copies the contents to $HOME/Downloads/instantclient_19_8 .

In Finder, eject the mounted Instant Client package.

If you have multiple Instant Client DMG packages mounted, you only need to run install_ic.sh once. It will copy all mounted Instant Client DMG packages at the same time.

Scripted Installation¶

Instant Client installation can alternatively be scripted, for example:

The Instant Client directory will be $HOME/Downloads/instantclient_19_8 .

Configure Oracle Instant Client¶

Call init_oracle_client() once in your application:

If you use optional Oracle configuration files such as tnsnames.ora , sqlnet.ora or oraaccess.xml with Oracle Instant Client, then put the files in an accessible directory, for example in /Users/your_username/oracle/your_config_dir . Then use:

Or set the environment variable TNS_ADMIN to that directory name.

Alternatively, put the files in the network/admin subdirectory of Oracle Instant Client, for example in /Users/your_username/Downloads/instantclient_19_8/network/admin . This is the default Oracle configuration directory for executables linked with this Instant Client.

Installing cx_Oracle without Internet Access¶

To install cx_Oracle on a computer that is not connected to the internet, download the appropriate cx_Oracle file from PyPI. Transfer this file to the offline computer and install it with:

Then follow the general cx_Oracle platform installation instructions to install Oracle client libraries.

Install Using GitHub¶

In order to install using the source on GitHub, use the following commands:

Note that if you download a source zip file directly from GitHub then you will also need to download an ODPI-C source zip file and extract it inside the directory called “odpi”.

cx_Oracle source code is also available from oss.oracle.com. This can be cloned with:

Install Using Source from PyPI¶

The source package can be downloaded manually from PyPI and extracted, after which the following commands should be run:

Upgrading from Older Versions¶

Review the release notes for deprecations and modify any affected code.

If you are upgrading from cx_Oracle 7 note these changes:

• The default character set used by cx_Oracle 8 is now “UTF-8”. Also, the character set component of the NLS_LANG environment variable is ignored. If you need to change the character set, then pass encoding and nendcoding parameters when creating a connection or connection pool. See Character Sets and Globalization .
• Any uses of type(var) need to be changed to var.type .
• Any uses of var.type is not None need to be changed to isinstance(var.type, cx_Oracle.ObjectType)
• Note that TIMESTAMP WITH TIME ZONE columns will now be reported as cx_Oracle.DB_TYPE_TIMESTAMP_TZ instead of cx_Oracle.TIMESTAMP in Cursor.description .
• Note that TIMESTAMP WITH LOCAL TIME ZONE columns will now be reported as cx_Oracle.DB_TYPE_TIMESTAMP_LTZ instead of cx_Oracle.TIMESTAMP in Cursor.description .
• Note that BINARY_FLOAT columns will now be reported as cx_Oracle.DB_TYPE_BINARY_FLOAT instead of cx_Oracle.NATIVE_DOUBLE in Cursor.description .

If you are upgrading from cx_Oracle 5 note these installation changes:

• When using Oracle Instant Client, you should not set ORACLE_HOME .
• On Linux, cx_Oracle 6 and higher no longer uses Instant Client RPMs automatically. You must set LD_LIBRARY_PATH or use ldconfig to locate the Oracle client library.
• PyPI no longer allows Windows installers or Linux RPMs to be hosted. Use the supplied cx_Oracle Wheels instead, or use RPMs from Oracle, see Installing cx_Oracle RPMs on Oracle Linux .

Installing cx_Oracle in Python 2В¶

cx_Oracle 7.3 was the last version with support for Python 2.

If you install cx_Oracle in Python 2 using the commands provided above, then cx_Oracle 7.3 will be installed. This is equivalent to using a command like:

For other installation options such as installing through a proxy, see instructions above. Make sure the Oracle Client libraries are in the system library search path because cx_Oracle 7 does not support the cx_Oracle.init_oracle_client() method and does not support loading the Oracle Client libraries from the directory containing the cx_Oracle module binary.

Installing cx_Oracle 5.3В¶

If you require cx_Oracle 5.3, download a Windows installer from PyPI or use python -m pip install cx-oracle==5.3 to install from source.

Very old versions of cx_Oracle can be found in the files section at SourceForce.

Troubleshooting¶

If installation fails:

• Use option -v with pip. Review your output and logs. Try to install using a different method. Google anything that looks like an error. Try some potential solutions.
• Was there a network connection error? Do you need to set the environment variables http_proxy and/or https_proxy ? Or try pip install —proxy=http://proxy.example.com:80 cx_Oracle —upgrade ?
• If upgrading gave no errors but the old version is still installed, try pip install cx_Oracle —upgrade —force-reinstall
• If you do not have access to modify your system version of Python, can you use pip install cx_Oracle —upgrade —user or venv?
• Do you get the error “ No module named pip ”? The pip module is builtin to Python but is sometimes removed by the OS. Use the venv module (builtin to Python 3.x) or virtualenv module instead.
• Do you get the error “ fatal error: dpi.h: No such file or directory ” when building from source code? Ensure that your source installation has a subdirectory called “odpi” containing files. If missing, review the section on Install Using GitHub.

If using cx_Oracle fails:

Do you get the error “ DPI-1047: Oracle Client library cannot be loaded ”?

Check that Python and your Oracle Client libraries are both 64-bit, or both 32-bit. The DPI-1047 message will tell you whether the 64-bit or 32-bit Oracle Client is needed for your Python.

Set the environment variable DPI_DEBUG_LEVEL to 64 and restart cx_Oracle. The trace messages will show how and where cx_Oracle is looking for the Oracle Client libraries.

At a Windows command prompt, this could be done with:

On Linux and macOS, you might use:

On Windows, if you used init_oracle_client() and have a full database installation, make sure this database is the currently configured database.

On Windows, if you are not using init_oracle_client() , then restart your command prompt and use set PATH to check the environment variable has the correct Oracle Client listed before any other Oracle directories.

On Windows, use the DIR command to verify that OCI.DLL exists in the directory passed to init_oracle_client() or set in PATH .

On Windows, check that the correct Windows Redistributables have been installed.

On Linux, check the LD_LIBRARY_PATH environment variable contains the Oracle Client library directory. If you are using Oracle Instant Client, a preferred alternative is to ensure a file in the /etc/ld.so.conf.d directory contains the path to the Instant Client directory, and then run ldconfig .

On macOS, make sure you are not using the bundled Python (use Homebrew or Python.org instead). If you are not using init_oracle_client() , then put the Oracle Instant Client libraries in

/lib or /usr/local/lib .

If you got “ DPI-1072: the Oracle Client library version is unsupported ”, then review the installation requirements. cx_Oracle needs Oracle client libraries 11.2 or later. Note that version 19 is not supported on Windows 7. Similar steps shown above for DPI-1047 may help.

If you have multiple versions of Python installed, make sure you are using the correct python and pip (or python3 and pip3) executables.

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