Introduction
In addition to normal ODBC support, the Unified ODBC functions in
PHP allow you to access several databases that have borrowed the
semantics of the ODBC API to implement their own API. Instead of
maintaining multiple database drivers that were all nearly
identical, these drivers have been unified into a single set of
ODBC functions.
The following databases are supported by the Unified ODBC
functions: Adabas D,
IBM DB2,
iODBC,
Solid, and
Sybase SQL Anywhere.
Note:
There is no ODBC involved when connecting to the above
databases. The functions that you use to speak natively to them
just happen to share the same names and syntax as the ODBC
functions. The exception to this is iODBC. Building PHP with iODBC
support enables you to use any ODBC-compliant drivers with your PHP
applications. iODBC is maintained by
OpenLink Software. More information on iODBC, as well as a
HOWTO, is available at www.iodbc.org.
Requirements
To access any of the supported databases you need to have
the required libraries installed.
Installation
Please see the Database installation
options chapter for more information about configuring PHP
with these databases.
The windows version of PHP
has built in support for this extension. You do not need to load any additional
extension in order to use these functions.
Runtime Configuration
The behaviour of these functions is affected by settings in php.ini.
Table 1. Unified ODBC Configuration Options
| Name | Default | Changeable |
|---|
| odbc.default_db * | NULL | PHP_INI_ALL |
| odbc.default_user * | NULL | PHP_INI_ALL |
| odbc.default_pw * | NULL | PHP_INI_ALL |
| odbc.allow_persistent | "1" | PHP_INI_SYSTEM |
| odbc.check_persistent | "1" | PHP_INI_SYSTEM |
| odbc.max_persistent | "-1" | PHP_INI_SYSTEM |
| odbc.max_links | "-1" | PHP_INI_SYSTEM |
| odbc.defaultlrl | "4096" | PHP_INI_ALL |
| odbc.defaultbinmode | "1" | PHP_INI_ALL |
Note:
Entries marked with * are not implemented yet.
For further details and definition of the PHP_INI_* constants see
ini_set().
Here is a short explanation of the configuration directives.
- odbc.default_db
string
ODBC data source to use if none is specified in
odbc_connect() or
odbc_pconnect().
- odbc.default_user
string
User name to use if none is specified in
odbc_connect() or
odbc_pconnect().
- odbc.default_pw
string
Password to use if none is specified in
odbc_connect() or
odbc_pconnect().
- odbc.allow_persistent
boolean
Whether to allow persistent ODBC connections.
- odbc.check_persistent
boolean
Check that a connection is still valid before reuse.
- odbc.max_persistent
integer
The maximum number of persistent ODBC connections per process.
- odbc.max_links
integer
The maximum number of ODBC connections per process, including
persistent connections.
- odbc.defaultlrl
integer
Handling of LONG fields. Specifies the number of bytes returned to
variables.
- odbc.defaultbinmode
integer
Handling of binary data.
Resource Types
This extension has no resource types defined.
Predefined Constants
The constants below are defined by this extension, and
will only be available when the extension has either
been compiled into PHP or dynamically loaded at runtime.