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.