Use PHP to operate Oracle database
11. Database connection
In the previous section, we have introduced some basic operating knowledge of PHP and MySQL databases. There are many related information about PHP and MySQL on the Internet. There are also the most tutorials. MySQL is free, which may attract many people. Due to its wide application, I don't want to go into details about the use of MySQL here. Oracle is widely used in enterprise applications, so we will use Oracle to further introduce the connection between PHP and database. We will certainly not mention the design principles of the Oracle database, as this is beyond the scope of our discussion.
PHP provides two sets of functions to connect to Oracle, namely ORA_ and OCI functions. The ORA_ function is slightly outdated. The OCI function update is said to be better. The usage syntax of the two is almost the same. As mentioned before, your PHP installation options should support the use of both.
To get more knowledge about installing an Apache server supporting PHP3 on Microsoft Windows platform and more knowledge about Oracle database, please check the following URL: www.csoft.net/~vsbabu/articles/oraphp.html.
11.1 Connection
if ($conn=Ora_Logon("user@TNSNAME","password"))
{
echo "n";
}
else
{
echo "Failed :-( Could not connect to databasen";
}
Ora_Logoff($conn);
phpinfo();
?>
The above code uses the Oracle database name and user name defined by TNSNAME (specified in your tnsnames.ora file) and password to connect to the database. On the basis of successful connection, the ora_logon function returns a non-zero connection ID and stores it in the variable $conn. 11.2 Query
Assume that the connection to the database is ready. Next we will come to the actual application of querying the database.The following code demonstrates a typical example of connecting and querying:
/*
* Connect to the database and execute the query
*/
function printoraerr($in_cur)
{
// Check whether Oracle has an error
// If there is an error, display it
// When the pointer is activated, call this function after each Oracle request
if(ora_errorcode($in_cur))
echo "Oracle code - ".ora_error($in_cur)."n";
return;
}
/**main program*/
if (!($conn=ora_logon ("user@TNSNAME","password")))
{
echo "Connection to database failedn";
exit;
}
echo "Connected as connection - $conn
n";
echo "Opening cursor ...
n";
$cursor=ora_open($conn); printoraerr($cursor);
echo "Opened cursor - $cursor
n";
$qry="select user,sysdate from dual";
echo "Parsing the query $qry ...
n";
ora_parse($cursor,$qry,0); printoraerr($cursor);
echo "Query parsed
n";
echo "Executing cursor ...
n";
ora_exec($cursor); printoraerr($cursor);
echo "Executing cursor
n";
echo " Fetching cursor ...
n";
while(ora_fetch($cursor))
{
$user=ora_getcolumn($cursor,0); printoraerr($cursor);
$sysdate=ora_getcolumn($cursor,1); printoraerr($cursor);
echo " row = $user, $sysdate
n";
}
echo "Fetched all records
n";
echo "Closing cursor ...
n";
ora_close($cursor);
echo "Closed cursor
n ";
echo "Logging off from oracle...
n";
ora_logoff($conn);
echo "Logged off from oracle
n";
? >
(Translator’s Note: The above code segment lacks comments, please refer to the Oracle database function section of the PHP Manual)
11.3 Display results
The following code demonstrates how to query the database and Output the result:
function printoraerr($in_cur, $conn)
{
// Check whether Oracle has an error
// If there is an error, display it
// This function is called after each Oracle request when the pointer is activated
// If it encountered an error, we exit immediately
if(ora_errorcode($in_cur))
{
echo "Oracle code - ".ora_error($in_cur)."
n";
ora_logoff($conn);
exit;
}
return;
}
function exequery($w_qry,$conn)
{
$cursor=ora_open($conn); printoraerr($cursor,$conn);
ora_parse($cursor,$w_qry,0); printoraerr($ cursor,$conn);
ora_exec($cursor); printoraerr($cursor,$conn);
$numrows=0;
$w_numcols=ora_numcols($cursor);
// display Head
echo "
n"; n"; n ";
for ($i=0;$i<$w_numcols;$i++)
{
$align=(ora_columntype($cursor,$i)=="NUMBER")?"RIGHT":"LEFT";
echo "t".ora_columnname($cursor,$i)." n";
}
echo "
while(ora_fetch($cursor))
{
echo "n"; n";
for ($i=0;$i<$w_numcols;$i++)
{
$align=(ora_columntype($cursor,$i)=="NUMBER")?"RIGHT":"LEFT";
if(ora_columntype($cursor,$i)=="LONG" )
echo " n"; ". <br>ora_getcolumn($cursor,$i)."
else
echo "".ora_getcolumn($cursor,$i)." n";
printoraerr($cursor,$conn) ;
}
$numrows++;
echo "
}
if ($numrows==0)
echo "< TD COLSPAN="$w_numcols">Query returned no records n";
else
{
echo "n"; n";
echo "Count n";
echo "$numrows n";
echo "
}
echo "
ora_close($cursor );
return;
}
//
if(!($conn=ora_logon("user@SID","password"))) )
{
echo "Error: Cannot connect to databasen";
exit;
}
$qry="SELECT
deptno "Dept"
,empno "Emp"
,empnm "Name"
,salary "Salary"
FROM
employee
ORDER BY 1,2";
exequery($qry);
ora_logoff($conn);
?>
(Translator's Note: The above code snippet lacks comments, please refer to the PHP Manual Oracle database function part)
11.4 Oracle login based on HTTP
Add the following code before the PHP page code to confirm Oracle login. Note that you must set $SID correctly.
if(!isset($PHP_AUTH_USER))
{
Header("WWW-authenticate: basic realm="$SID"");
Header("HTTP/ 1.0 401 Unauthorized");
$title="Login Instructions";
echo "
n";
You are not authorized to enter the site
exit;
}
else
{
if (!($conn=ora_logon("$PHP_AUTH_USER@$SID",$PHP_AUTH_PW)))
{
Header(" WWW-authenticate: basic realm="$SID"");
Header("HTTP/1.0 401 Unauthorized");
$title="Login Instructions";
echo "
n";
You are not authorized to enter the site
exit;
}
}
?>