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oci_connect
Connect to an Oracle database
Description
resourcefalse oci_connect(
string $username,
string $password,
stringnull $connection_string = null,
string $encoding = "",
int $session_mode = OCI_DEFAULT
)
For performance, most applications should use persistent connections
with oci_pconnect instead
of oci_connect.
See Connection Handling for general
information on connection management and connection pooling.
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 transactions in one handle are
also in the other handles, because they use the
same underlying database connection. If two
handles need to be transactionally isolated from each other, use
oci_new_connect instead.
Parameters
-
username
-
The Oracle user name.
-
password
-
The password for username.
-
connection_string
-
Contains
the Oracle instance to connect to. It can be
an » Easy Connect
string, or a Connect Name from
the tnsnames.ora file, or the name of a local
Oracle instance.
If not specified or null, PHP uses
environment variables such as TWO_TASK (on Linux)
or LOCAL (on Windows)
and ORACLE_SID to determine the
Oracle instance to connect to.
To use the Easy Connect naming method, PHP must be linked with Oracle
10g or greater Client libraries. The Easy Connect string for Oracle
10g is of the form:
[//]host_name[:port][/service_name]. From Oracle
11g, the syntax is:
[//]host_name[:port][/service_name][:server_type][/instance_name].
Further options were introduced with Oracle 19c, including timeout and keep-alive
settings. Refer to Oracle documentation. Service names can be found by running
the Oracle utility lsnrctl status on the database server
machine.
The tnsnames.ora file can be in the Oracle Net search path,
which
includes /your/path/to/instantclient/network/admin, $ORACLE_HOME/network/admin
and /etc. Alternatively set TNS_ADMIN
so that $TNS_ADMIN/tnsnames.ora is read. Make sure the web
daemon has read access to the file.
-
encoding
-
Determines
the character set used by the Oracle Client libraries. The character
set does not need to match the character set used by the database. If
it doesn't match, Oracle will do its best to convert data to and from
the database character set. Depending on the character sets this may
not give usable results. Conversion also adds some time overhead.
If not specified, the
Oracle Client libraries determine a character set from
the NLS_LANG environment variable.
Passing this parameter can
reduce the time taken to connect.
-
session_mode
-
This
parameter is available since version PHP 5 (PECL OCI8 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.
PHP 5.3 (PECL OCI8 1.3.4) introduced the
OCI_CRED_EXT mode value. This tells Oracle to use
External or OS authentication, which must be configured in the
database. The OCI_CRED_EXT flag can only be used
with username of "/" and a empty password.
oci8.privileged_connect
may be On or Off.
OCI_CRED_EXT may be combined with the
OCI_SYSOPER or
OCI_SYSDBA modes.
OCI_CRED_EXT is not supported on Windows for
security reasons.
Return Values
Returns a connection identifier or false on error.
Examples
Example #1 Basic oci_connect using Easy Connect syntax
<?php
// Connects to the XE service (i.e. database) on the "localhost" machine
$conn = oci_connect('hr', 'welcome', 'localhost/XE');
if (!$conn) {
$e = oci_error();
trigger_error(htmlentities($e['message'], ENT_QUOTES), E_USER_ERROR);
}
$stid = oci_parse($conn, 'SELECT * FROM employees');
oci_execute($stid);
echo "<table border='1'>\n";
while ($row = oci_fetch_array($stid, OCI_ASSOC+OCI_RETURN_NULLS)) {
echo "<tr>\n";
foreach ($row as $item) {
echo " <td>" . ($item !== null ? htmlentities($item, ENT_QUOTES) : " ") . "</td>\n";
}
echo "</tr>\n";
}
echo "</table>\n";
?>
Example #2 Basic oci_connect using a Network Connect name
<?php
// Connects to the MYDB database described in tnsnames.ora file,
// One example tnsnames.ora entry for MYDB could be:
// MYDB =
// (DESCRIPTION =
// (ADDRESS = (PROTOCOL = TCP)(HOST = mymachine.oracle.com)(PORT = 1521))
// (CONNECT_DATA =
// (SERVER = DEDICATED)
// (SERVICE_NAME = XE)
// )
// )
$conn = oci_connect('hr', 'welcome', 'MYDB');
if (!$conn) {
$e = oci_error();
trigger_error(htmlentities($e['message'], ENT_QUOTES), E_USER_ERROR);
}
$stid = oci_parse($conn, 'SELECT * FROM employees');
oci_execute($stid);
echo "<table border='1'>\n";
while ($row = oci_fetch_array($stid, OCI_ASSOC+OCI_RETURN_NULLS)) {
echo "<tr>\n";
foreach ($row as $item) {
echo " <td>" . ($item !== null ? htmlentities($item, ENT_QUOTES) : " ") . "</td>\n";
}
echo "</tr>\n";
}
echo "</table>\n";
?>
Example #3 oci_connect with an explicit character set
<?php
$conn = oci_connect('hr', 'welcome', 'localhost/XE', 'AL32UTF8');
if (!$conn) {
$e = oci_error();
trigger_error(htmlentities($e['message'], ENT_QUOTES), E_USER_ERROR);
}
$stid = oci_parse($conn, 'SELECT * FROM employees');
oci_execute($stid);
echo "<table border='1'>\n";
while ($row = oci_fetch_array($stid, OCI_ASSOC+OCI_RETURN_NULLS)) {
echo "<tr>\n";
foreach ($row as $item) {
echo " <td>" . ($item !== null ? htmlentities($item, ENT_QUOTES) : " ") . "</td>\n";
}
echo "</tr>\n";
}
echo "</table>\n";
?>
Example #4 Using multiple calls to oci_connect
<?php
$c1 = oci_connect("hr", "welcome", 'localhost/XE');
$c2 = oci_connect("hr", "welcome", 'localhost/XE');
// Both $c1 and $c2 show the same PHP resource id meaning they use the
// same underlying database connection
echo "c1 is $c1<br>\n";
echo "c2 is $c2<br>\n";
function create_table($conn)
{
$stmt = oci_parse($conn, "create table hallo (test varchar2(64))");
oci_execute($stmt);
echo "Created table<br>\n";
}
function drop_table($conn)
{
$stmt = oci_parse($conn, "drop table hallo");
oci_execute($stmt);
echo "Dropped table<br>\n";
}
function insert_data($connname, $conn)
{
$stmt = oci_parse($conn, "insert into hallo
values(to_char(sysdate,'DD-MON-YY HH24:MI:SS'))");
oci_execute($stmt, OCI_DEFAULT);
echo "$connname inserted row without committing<br>\n";
}
function rollback($connname, $conn)
{
oci_rollback($conn);
echo "$connname rollback<br>\n";
}
function select_data($connname, $conn)
{
$stmt = oci_parse($conn, "select * from hallo");
oci_execute($stmt, OCI_DEFAULT);
echo "$connname ----selecting<br>\n";
while (oci_fetch($stmt)) {
echo " " . oci_result($stmt, "TEST") . "<br>\n";
}
echo "$connname ----done<br>\n";
}
create_table($c1);
insert_data('c1', $c1); // Insert a row using c1
sleep(2); // sleep to show a different timestamp for the 2nd row
insert_data('c2', $c2); // Insert a row using c2
select_data('c1', $c1); // Results of both inserts are returned
select_data('c2', $c2); // Results of both inserts are returned
rollback('c1', $c1); // Rollback using c1
select_data('c1', $c1); // Both inserts have been rolled back
select_data('c2', $c2);
drop_table($c1);
// Closing one of the connections makes the PHP variable unusable, but
// the other could be used
oci_close($c1);
echo "c1 is $c1<br>\n";
echo "c2 is $c2<br>\n";
// Output is:
// c1 is Resource id #5
// c2 is Resource id #5
// Created table
// c1 inserted row without committing
// c2 inserted row without committing
// c1 ----selecting
// 09-DEC-09 12:14:43
// 09-DEC-09 12:14:45
// c1 ----done
// c2 ----selecting
// 09-DEC-09 12:14:43
// 09-DEC-09 12:14:45
// c2 ----done
// c1 rollback
// c1 ----selecting
// c1 ----done
// c2 ----selecting
// c2 ----done
// Dropped table
// c1 is
// c2 is Resource id #5
?>
Notes
Note:
An incorrectly installed or configured OCI8 extension will often
manifest itself as a connection problem or error.
See Installing/Configuring for
troubleshooting information.
See Also
- oci_pconnect
- oci_new_connect
- oci_close
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