iODBC Driver Manager

Copyright (C) 1995 Ke Jin kejin@empress.com. Copyright (C) 1996-2024 OpenLink Software iodbc@openlinksw.com.

License

Copyright 1996-2024 OpenLink Software

This software is released under either the GNU Library General Public License (see LICENSE.LGPL) or the BSD License (see LICENSE.BSD).

Note: The only valid version of the GPL license as far as this project is concerned is the original GNU General Public License Version 2, dated June 1991.

Contributions

While not mandated by the BSD license, any patches you make to the iODBC project may be contributed back into the project at your discretion. Contributions will benefit the Open Source and Data Access community as a whole. Submissions may be made via the iODBC Github project or via email to iodbc@openlinksw.com.

Introduction

Welcome to the iODBC driver manager maintained by OpenLink Software.

This kit will provide you with everything you need to develop ODBC-compliant applications under Unix without having to pay royalties to other parties.

This kit consists of a number of parts:

• The iODBC driver manager. This is a complete implementation of an ODBC driver manager, released under either the GNU Library General Public License or the BSD License. We fully comply with these licenses by giving you this product in source form (as well as the binary form). You can download the latest version of the driver manager from the iODBC website.

• A simple example application, iodbctest.c, which gives you a command-line interface to SQL. You can fit this to your purposes, but at the very least this is useful for verification of your ODBC installation.

You can use either part stand-alone, if you wish.

An ODBC driver is still needed to affect your connection architecture. You may build a driver with the iODBC components or obtain an ODBC driver from a commercial vendor. OpenLink Software produces cross-platform commercial drivers as well as maintaining the iODBC distribution: evaluation copies may be obtained via download from the OpenLink Software website. Any ODBC-compliant driver will work with the iODBC Driver Manager.

You can see the iODBC website for pointers to various ODBC drivers.

Installation of run-time distribution

You have probably already unpacked this distribution. The next step is to make sure that your applications can find all the dynamic link libraries. Depending on your system's implementation of dynamic link libraries, you have a number of options:

• Install the libraries in a directory that is searched by your linker by default. Typical locations are /usr/lib and /usr/local/lib.

• Install the libraries in some other place, and make sure that the environment variable your dynamic linker uses to find extra locations for dynamic link libraries. Most systems use the environment variable LD_LIBRARY_PATH to this end. Known exceptions include AIX which uses LIBPATH, and HP/UX which uses SHLIB_PATH for 32-bit libraries.

If your system has a C compiler, you can verify the installation by compiling the iodbctest program. Otherwise, you may have ODBC applications installed on your system which you can use.

Configuration of run-time distribution

The iODBC driver manager looks for a file ~/.odbc.ini, where the tilde stands for the user's home directory. This file initially contains only a default section where you can select which driver library to use. Copy the odbc.ini file from the examples directory to ~/.odbc.ini and make sure the right path and filename is used for your installation.

A data source is a section (enclosed in square brackets), and the attributes for a data source are given within this section. The most important attribute to iODBC for each datasource is the Driver attribute. This must point to the shared library for the ODBC driver associated with the data source.

For example, the OpenLink Enterprise Edition (Multi-Tier) ODBC drivers have a number of attributes which can be set for a data source. Here is a description:

Apart from these data source-specific settings, you may add a section called [Communications], which you may use to tune the OpenLink Enterprise Edition (Multi-Tier) driver further:

iODBC driver manager platform availability

The iODBC driver manager has been ported to following platforms:

As the iODBC driver manager uses autoconf/automake/libtool, it should be portable to most modern UNIX-like OS out of the box. However, if you do need to make changes to the code or the configuration files, we would appreciate it if you would share your changes with the rest of the internet community by mailing your patches to iodbc@openlinksw.com, so we can include them for the next build.

Porting the iODBC driver manager to some non-UNIX-like operating systems, such as the Windows family (3.x, 95, NT, 200x, etc.), IBM OS/2, or Mac Classic, is supported, but has not been compiled or tested recently. Of course, you will need to supply a make/build file and a short LibMain for creating the iodbc.dll.

How to build the iODBC driver manager

Users of macOS should read the separate README_MACOSX document for more detail of porting to this platform.

Users of all other UNIX-like OS:

1. Run configure to adjust to target platform
2. Run make
3. Run make install

The configure program will examine your system for various compiler flags, system options, etc. In some cases, extra flags need to be added for the C compiler to work properly; for instance, on HP systems, you may need:

$ CFLAGS="-Ae -O" ./configure --prefix=/usr/local ..........

File Hierarchy

Note that the path of the system wide odbc.ini file is calculated as follows (based on flags to ./configure):

no --prefix                     default is /etc/odbc.ini
--prefix=/usr                   /etc/odbc.ini
--prefix=/xxx/yyy               /xxx/yyy/etc/odbc.ini
--sysconfdir=/xxx/yyy           /xxx/yyy/odbc.ini
--with-iodbc-inidir=/xxx/yyy    /xxx/yyy/odbc.ini

If the --with-layout= option is set, then the prefix and sysconfdir parameters will be changed accordingly. Currently, this parameter understands values of gentoo, redhat, gnu, debian, or opt (with everything going into /opt/iodbc/). If both are specified, --prefix argument will overrule --with-layout.

Example

$ ./configure --prefix=/usr/local --with-iodbc-inidir=/etc
    ...
    ...
    ...
$ make
    ...
    ...
    ...
$ su
# make install
    ...
    ...
    ...

odbc.ini

Driver manager and drivers use the odbc.ini file or connection string when establishing a data source connection. On Windows, odbc.ini is located in the Windows directory.

On UNIX-like OS, the iODBC driver manager looks for the odbc.ini file in the following sequence:

1. check environment variable ODBCINI

2. check $HOME/.odbc.ini

3. check home in /etc/passwd and try .odbc.ini in there

4. system-wide odbc.ini (settable at configuration time)

Item 1 is the easiest, as most drivers will also look at this variable.

The format of odbc.ini (or ~/.odbc.ini) is defined as:

odbc.ini            ::= data_source_list

data_source_list    ::= /* empty */
                     | data_source '\n' data_source_list

data_source         ::= '[' data_source_name ']' '\n' data_source_desc

data_source_name    ::= 'default' | [A-Za-z]*[A-Za-z0-9_]*

data_source_desc    ::= /* empty */
                     | attrib_desc '\n' data_source_desc

addrib_desc         ::= Attrib '=' attrib_value

Attrib              ::= 'Driver' | 'PID' | 'UID' | driver_def_attrib

driver_def_attrib   ::= [A-Za-z]*[A-Za-z0-9_]*

An example of an odbc.ini file:

;
;  odbc.ini
;
[ODBC Data Sources]
Myodbc          = Myodbc
Sample          = OpenLink Generic ODBC Driver
Virtuoso        = Virtuoso

[ODBC]
TraceFile       = /tmp/odbc.trace
Trace           = 0        ; set to 1 to enable tracing

[Sample]
Driver          = /usr/local/openlink/lib/oplodbc.so.1
Description     = Sample OpenLink DSN
Host            = localhost
UserName        = openlink
Password        = xxxx
ServerType      = Oracle 8.1.x
Database        =
FetchBufferSize = 99
ReadOnly        = no

[Virtuoso]
Driver          = /usr/local/virtuoso/lib/virtodbc.so.1
Address         = localhost:1112
Database        = Demo

[Myodbc]
Driver          = /usr/lib/libmyodbc.so
HOST            = localhost

[Default]
Driver          = /usr/local/openlink/lib/oplodbc.so.1

Tracing

The iODBC driver manager traces driver's ODBC call invoked by the driver manager. Default tracing file is ./odbc.log. Tracing option (i.e., on/off or optional tracing file name) can be set in odbc.ini file under the [ODBC] heading, as:

[ODBC]
TraceFile = <optional_trace_file>
Trace = ON | On | on | 1 | OFF | Off | off | 0

If <optional_trace_file> is stderr or stdout, i.e. --

TraceFile = stderr

-- or --

TraceFile = stdout

-- the tracing message will go to the terminal screen (if available).

Further Information Sources

• iODBC Website containing binaries, sources and documentation.

• iODBC Project page on GitHub containing source archives, GIT tree, issues forum.

• iODBC Project page on Sourceforge containing source archives, GIT tree, mailing lists, forums, bug reports.

• OpenLink Software Website containing free trials and support for OpenLink's ODBC drivers.

• Microsoft ODBC Documentation containing the ODBC API Reference Guide.