<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision$ -->
<chapter xml:id="oci8.examples" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink">
 &reftitle.examples;
 <para>
  These examples connect as the <literal>HR</literal> user, which is
  the sample &quot;Human Resources&quot; schema supplied with the
  Oracle database. The account may need to be unlocked and the
  password reset before you can use it.
 </para>

 <para>
  The examples connect to the <literal>XE</literal> database on your
  machine.  Change the connect string to your database before running
  the examples.
 </para>

 <example>
  <title>Basic query</title>
  <para>
   This shows querying and displaying results.  Statements in OCI8 use
   a prepare-execute-fetch sequence of steps.
  </para>
  <programlisting role="php">
<![CDATA[
<?php

$conn = oci_connect('hr', 'welcome', 'localhost/XE');
if (!$conn) {
    $e = oci_error();
    trigger_error(htmlentities($e['message'], ENT_QUOTES), E_USER_ERROR);
}

// Prepare the statement
$stid = oci_parse($conn, 'SELECT * FROM departments');
if (!$stid) {
    $e = oci_error($conn);
    trigger_error(htmlentities($e['message'], ENT_QUOTES), E_USER_ERROR);
}

// Perform the logic of the query
$r = oci_execute($stid);
if (!$r) {
    $e = oci_error($stid);
    trigger_error(htmlentities($e['message'], ENT_QUOTES), E_USER_ERROR);
}

// Fetch the results of the query
print "<table border='1'>\n";
while ($row = oci_fetch_array($stid, OCI_ASSOC+OCI_RETURN_NULLS)) {
    print "<tr>\n";
    foreach ($row as $item) {
        print "    <td>" . ($item !== null ? htmlentities($item, ENT_QUOTES) : "&nbsp;") . "</td>\n";
    }
    print "</tr>\n";
}
print "</table>\n";

oci_free_statement($stid);
oci_close($conn);

?>
]]>
  </programlisting>
 </example>

 <example>
  <title>Inserting with bind variables</title>
  <para>
   Bind variables improve performance by allowing reuse of execution
   contexts and caches.  Bind variables improve security by preventing
   some kinds of SQL Injection problems.
  </para>
  <programlisting role="php">
<![CDATA[
<?php

// Before running, create the table:
//   CREATE TABLE MYTABLE (mid NUMBER, myd VARCHAR2(20));

$conn = oci_connect('hr', 'welcome', 'localhost/XE');
if (!$conn) {
    $e = oci_error();
    trigger_error(htmlentities($e['message'], ENT_QUOTES), E_USER_ERROR);
}

$stid = oci_parse($conn, 'INSERT INTO MYTABLE (mid, myd) VALUES(:myid, :mydata)');

$id = 60;
$data = 'Some data';

oci_bind_by_name($stid, ':myid', $id);
oci_bind_by_name($stid, ':mydata', $data);

$r = oci_execute($stid);  // executes and commits

if ($r) {
    print "One row inserted";
}

oci_free_statement($stid);
oci_close($conn);

?>
]]>
  </programlisting>
 </example>

 <example>
  <title>Binding in the WHERE clause of a query</title>
  <para>
   This shows a single scalar bind.
  </para>
  <programlisting role="php">
<![CDATA[
<?php

$conn = oci_connect("hr", "hrpwd", "localhost/XE");
if (!$conn) {
    $m = oci_error();
    trigger_error(htmlentities($m['message']), E_USER_ERROR);
}

$sql = 'SELECT last_name FROM employees WHERE department_id = :didbv ORDER BY last_name';
$stid = oci_parse($conn, $sql);
$didbv = 60;
oci_bind_by_name($stid, ':didbv', $didbv);
oci_execute($stid);
while (($row = oci_fetch_array($stid, OCI_ASSOC)) != false) {
    echo $row['LAST_NAME'] ."<br>\n";
}

// Output is
//    Austin
//    Ernst
//    Hunold
//    Lorentz
//    Pataballa

oci_free_statement($stid);
oci_close($conn);

?>
]]>
  </programlisting>
 </example>

 <example>
  <title>Inserting and fetching a CLOB</title>
  <para>
   For large data use binary long object (BLOB) or character long
   object (CLOB) types.  This example uses CLOB.
  </para>
  <programlisting role="php">
<![CDATA[
<?php

// Before running, create the table:
//     CREATE TABLE MYTABLE (mykey NUMBER, myclob CLOB);

$conn = oci_connect('hr', 'welcome', 'localhost/XE');
if (!$conn) {
    $e = oci_error();
    trigger_error(htmlentities($e['message'], ENT_QUOTES), E_USER_ERROR);
}

$mykey = 12343;  // arbitrary key for this example;

$sql = "INSERT INTO mytable (mykey, myclob)
        VALUES (:mykey, EMPTY_CLOB())
        RETURNING myclob INTO :myclob";

$stid = oci_parse($conn, $sql);
$clob = oci_new_descriptor($conn, OCI_D_LOB);
oci_bind_by_name($stid, ":mykey", $mykey, 5);
oci_bind_by_name($stid, ":myclob", $clob, -1, OCI_B_CLOB);
oci_execute($stid, OCI_NO_AUTO_COMMIT);
$clob->save("A very long string");

oci_commit($conn);

// Fetching CLOB data

$query = 'SELECT myclob FROM mytable WHERE mykey = :mykey';

$stid = oci_parse ($conn, $query);
oci_bind_by_name($stid, ":mykey", $mykey, 5);
oci_execute($stid);

print '<table border="1">';
while ($row = oci_fetch_array($stid, OCI_ASSOC+OCI_RETURN_LOBS)) {
    print '<tr><td>'.$row['MYCLOB'].'</td></tr>';
    // In a loop, freeing the large variable before the 2nd fetch reduces PHP's peak memory usage
    unset($row);  
}
print '</table>';

?>
]]>
  </programlisting>
 </example>

 <example>
  <title>Using a PL/SQL stored function</title>
  <para>
   You must bind a variable for the return value and optionally for
   any PL/SQL function arguments.
  </para>
  <programlisting role="php">
<![CDATA[
<?php

/*
  Before running the PHP program, create a stored function in
  SQL*Plus or SQL Developer:

  CREATE OR REPLACE FUNCTION myfunc(p IN NUMBER) RETURN NUMBER AS
  BEGIN
      RETURN p * 3;
  END;

*/

$conn = oci_connect('hr', 'welcome', 'localhost/XE');
if (!$conn) {
    $e = oci_error();
    trigger_error(htmlentities($e['message'], ENT_QUOTES), E_USER_ERROR);
}

$p = 8;

$stid = oci_parse($conn, 'begin :r := myfunc(:p); end;');
oci_bind_by_name($stid, ':p', $p);
oci_bind_by_name($stid, ':r', $r, 40);

oci_execute($stid);

print "$r\n";   // prints 24

oci_free_statement($stid);
oci_close($conn);

?>
]]>
  </programlisting>
 </example>

 <example>
  <title>Using a PL/SQL stored procedure</title>
  <para>
   With stored procedures, you should bind variables for any arguments.
  </para>
  <programlisting role="php">
<![CDATA[
<?php

/*
  Before running the PHP program, create a stored procedure in
  SQL*Plus or SQL Developer:

  CREATE OR REPLACE PROCEDURE myproc(p1 IN NUMBER, p2 OUT NUMBER) AS
  BEGIN
      p2 := p1 * 2;
  END;

*/

$conn = oci_connect('hr', 'welcome', 'localhost/XE');
if (!$conn) {
    $e = oci_error();
    trigger_error(htmlentities($e['message'], ENT_QUOTES), E_USER_ERROR);
}

$p1 = 8;

$stid = oci_parse($conn, 'begin myproc(:p1, :p2); end;');
oci_bind_by_name($stid, ':p1', $p1);
oci_bind_by_name($stid, ':p2', $p2, 40);

oci_execute($stid);

print "$p2\n";   // prints 16

oci_free_statement($stid);
oci_close($conn);

?>
]]>
  </programlisting>
 </example>

 <example>
  <title>Calling a PL/SQL function that returns a <literal>REF CURSOR</literal></title>
  <para>
   Each returned value from the query is a <literal>REF
   CURSOR</literal> that can be fetched from.
  </para>
  <programlisting role="php">
<![CDATA[
<?php
/*
  Create the PL/SQL stored function as:

  CREATE OR REPLACE FUNCTION myfunc(p1 IN NUMBER) RETURN SYS_REFCURSOR AS
      rc SYS_REFCURSOR;
  BEGIN
      OPEN rc FOR SELECT city FROM locations WHERE ROWNUM < p1;
      RETURN rc;
  END;
*/

$conn = oci_connect('hr', 'welcome', 'localhost/XE');

$stid = oci_parse($conn, 'SELECT myfunc(5) AS mfrc FROM dual');
oci_execute($stid);

echo "<table border='1'>\n";
while (($row = oci_fetch_array($stid, OCI_ASSOC))) {
    echo "<tr>\n";
    $rc = $row['MFRC'];
    oci_execute($rc);  // returned column value from the query is a ref cursor
    while (($rc_row = oci_fetch_array($rc, OCI_ASSOC))) {   
        echo "    <td>" . $rc_row['CITY'] . "</td>\n";
    }
    oci_free_statement($rc);
    echo "</tr>\n";
}
echo "</table>\n";

// Output is:
//   Beijing
//   Bern
//   Bombay
//   Geneva

oci_free_statement($stid);
oci_close($conn);

?>
]]>
  </programlisting>
 </example>
</chapter>

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