Returns a connection identifier needed for most other OCI calls.
The Oracle user name.
The password for
This optional parameter can either contain the name of the local Oracle instance or the name of the entry in tnsnames.ora.
If the not specified, PHP uses environment variables ORACLE_SID and TWO_TASK to determine the name of local Oracle instance and location of tnsnames.ora accordingly.
Using Oracle server version 9.2 and greater, you can
charset parameter, which will be used in the new
connection. If you're using Oracle server < 9.2, this parameter will be ignored
and NLS_LANG environment variable will be used instead.
This parameter is available since version 1.1 and accepts the following values: OCI_DEFAULT, OCI_SYSOPER and OCI_SYSDBA. If either OCI_SYSOPER or OCI_SYSDBA were specified, this function will try to establish privileged connection using external credentials. Privileged connections are disabled by default. To enable them you need to set oci8.privileged_connect to On.
Example 1. oci_connect() example
Note: If you're using PHP with Oracle Instant Client, you can use easy connect naming method described here: http://download-west.oracle.com/docs/cd/B12037_01/network.101/b10775/naming.htm#i498306. Basically this means you can specify "//db_host[:port]/database_name" as database name. But if you want to use the old way of naming you must set either ORACLE_HOME or TNS_ADMIN.
Note: The second and subsequent calls to oci_connect() with the same parameters will return the connection handle returned from the first call. This means that queries issued against one handle are also applied to the other handles, because they are the same handle. This behaviour is demonstrated in Example 1 below. If you require two handles to be transactionally isolated from each other, you should use oci_new_connect() instead.
Note: In PHP versions before 5.0.0 you must use ocilogon() instead. This name still can be used, it was left as the alias of oci_connect() for downwards compatability. This, however, is deprecated and not recommended.