PDO_ODBC is a driver that implements the PHP Data Objects (PDO) interface to enable access from PHP to databases through ODBC drivers or through the IBM DB2 Call Level Interface (DB2 CLI) library. PDO_ODBC currently supports three different "flavours" of database drivers:
Supports access to IBM DB2 Universal Database, Cloudscape, and Apache Derby servers through the free DB2 express-C client.
Supports access to database servers through the unixODBC driver manager and the database's own ODBC drivers.
Offers a compile option for ODBC driver managers that are not explicitly supported by PDO_ODBC.
On Windows, php_pdo_odbc.dll has to be enabled as extension in php.ini. It is linked against the Windows ODBC Driver Manager so that PHP can connect to any database cataloged as a System DSN.
PDO_ODBC is included in the PHP source. You can compile the PDO_ODBC extension as either a static or shared module using the following configure commands.
./configure --with-pdo-odbc=ibm-db2,/opt/IBM/db2/V8.1/
If you do not supply a location for the DB2 libraries and headers to the configure command, PDO_ODBC defaults to /home/db2inst1/sqllib.
./configure --with-pdo-odbc=unixODBC,/usr/local
./configure --with-pdo-odbc=generic,/usr/local,libname,ldflags,cflags
As constantes abaixo são definidas por este driver e só estarão disponíveis quando a extensão tiver sido compilada no PHP ou tiver sido carregada dinamicamente em tempo de execução. Além disso, estas constantes específicas do driver só devem ser usadas se este driver estiver sendo usado. Usar atributos específicos de um driver com outro driver pode resultar em comportamento inesperado. PDO::getAttribute() pode ser usada para obter o atributo PDO::ATTR_DRIVER_NAME
para verificar o driver, se o código puder ser executado com vários drivers.
PDO_ODBC_TYPE
(string) PDO::ODBC_ATTR_USE_CURSOR_LIBRARY
(int) This option controls whether the ODBC cursor library is used. The ODBC cursor library supports some advanced ODBC features (e.g. block scrollable cursors), which may not be implemented by the driver. The following values are supported:
PDO::ODBC_SQL_USE_IF_NEEDED
(the default): use the ODBC cursor library when needed.
PDO::ODBC_SQL_USE_DRIVER
: never use the ODBC cursor library.
PDO::ODBC_SQL_USE_ODBC
: always use the ODBC cursor library.
PDO::ODBC_ATTR_ASSUME_UTF8
(bool) Windows only. If true
, UTF-16 encoded character data (CHAR
, VARCHAR
and LONGVARCHAR
) is converted to UTF-8 when reading from or writing data to the database. If false
(the default), character encoding conversion may be done by the driver.
O comportamento destas funções é afetado pelas configurações do php.ini.
Nome | Padrão | Modificável | Registro de Alterações |
---|---|---|---|
pdo_odbc.connection_pooling | "strict" | INI_ALL | |
pdo_odbc.db2_instance_name | NULL | INI_SYSTEM | Este recurso defasado certamente será removido no futuro. |
Aqui está uma breve explicação das diretivas de configuração.
pdo_odbc.connection_pooling
string Whether to pool ODBC connections. Can be one of "strict"
, "relaxed"
or "off"
(equals to ""
). The parameter describes how strict the connection manager should be when matching connection parameters to existing pooled connections. strict
is the recommend default, and will result in the use of cached connections only when all the connection parameters match exactly. relaxed
will result in the use of cached connections when similar connection parameters are used. This can result in increased use of the cache, at the risk of bleeding connection information between (for example) virtual hosts.
This setting can only be changed from the php.ini file, and affects the entire process; any other modules loaded into the process that use the same ODBC libraries will be affected too, including the Unified ODBC extension.
relaxed
matching should not be used on a shared server, for security reasons.
Leave this setting at the default strict
setting unless you have good reason to change it.
pdo_odbc.db2_instance_name
string If you compile PDO_ODBC using the db2
flavour, this setting sets the value of the DB2INSTANCE environment variable on Linux and UNIX operating systems to the specified name of the DB2 instance. This enables PDO_ODBC to resolve the location of the DB2 libraries and make cataloged connections to DB2 databases.
This setting can only be changed from the php.ini file, and affects the entire process; any other modules loaded into the process that use the same ODBC libraries will be affected too, including the Unified ODBC extension.
This setting has no effect on Windows.