php-doc-en/reference/oci8/functions/oci-bind-by-name.xml
Jakub Vrana f453f7036c Add PHP tags to <programlisting>
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2010-07-09 09:38:38 +00:00

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<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision$ -->
<refentry xml:id="function.oci-bind-by-name" xmlns="http://docbook.org/ns/docbook">
<refnamediv>
<refname>oci_bind_by_name</refname>
<refpurpose>Binds a PHP variable to an Oracle placeholder</refpurpose>
</refnamediv>
<refsect1 role="description">
&reftitle.description;
<methodsynopsis>
<type>bool</type><methodname>oci_bind_by_name</methodname>
<methodparam><type>resource</type><parameter>statement</parameter></methodparam>
<methodparam><type>string</type><parameter>bv_name</parameter></methodparam>
<methodparam><type>mixed</type><parameter role="reference">variable</parameter></methodparam>
<methodparam choice="opt"><type>int</type><parameter>maxlength</parameter><initializer>-1</initializer></methodparam>
<methodparam choice="opt"><type>int</type><parameter>type</parameter><initializer>SQLT_CHR</initializer></methodparam>
</methodsynopsis>
<para>
Binds a PHP variable <parameter>variable</parameter> to the Oracle
bind variable placeholder <parameter>bv_name</parameter>. Binding
is important for Oracle database performance and also as a way to
avoid SQL Injection security issues.
</para>
<para>
Binding allows the database to reuse the statement context and
caches from previous executions of the statement, even if another
user or process originally executed it. Binding reduces SQL
Injection concerns because the data associated with a bind
variable is never treated as part of the SQL statement. It does
not need quoting or escaping.
</para>
<para>
PHP variables that have been bound can be changed and the
statement re-executed without needing to re-parse the statement or
re-bind.
</para>
<para>
In Oracle, bind variables are commonly divided
into <literal>IN</literal> binds for values that are passed into
the database, and <literal>OUT</literal> binds for values that are
returned to PHP. A bind variable may be
both <literal>IN</literal> and <literal>OUT</literal>. Whether a
bind variable will be used for input or output is determined at
run-time.
</para>
<para>
You must specify <parameter>maxlength</parameter> when using
an <literal>OUT</literal> bind so that PHP allocates enough memory
to hold the returned value.
</para>
<para>
For <literal>IN</literal> binds it is recommended to set
the <parameter>maxlength</parameter> length if the statement is
re-executed multiple times with different values for the PHP
variable. Otherwise Oracle may truncate data to the length of the
initial PHP variable value. If you don't know what the maximum
length will be, then re-call <function>oci_bind_by_name</function>
with the current data size prior to
each <function>oci_execute</function> call. Binding an
unnecessarily large length will have an impact on process memory
in the database.
</para>
<para>
A bind call tells Oracle which memory address to read data from.
For <literal>IN</literal> binds that address needs to contain
valid data when <function>oci_execute</function> is called. This
means that the variable bound must remain in scope until
execution. If it doesn't, unexpected results or errors such as
"ORA-01460: unimplemented or unreasonable conversion requested"
may occur. For <literal>OUT</literal> binds one symptom is no
value being set in the PHP variable.
</para>
<para>
For a statement that is repeatedly executed, binding values that
never change may reduce the ability of the Oracle optimizer to
choose the best statement execution plan. Long running statements
that are rarely re-executed may not benefit from binding. However
in both cases, binding might be safer than joining strings into a
SQL statement, as this can be a security risk if unfiltered user
text is concatenated.
</para>
</refsect1>
<refsect1 role="parameters">
&reftitle.parameters;
<para>
<variablelist>
<varlistentry>
<term><parameter>statement</parameter></term>
<listitem>
<para>
A valid OCI8 statement identifer.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>bv_name</parameter></term>
<listitem>
<para>
The colon-prefixed bind variable placeholder used in the
statement. The colon is optional
in <parameter>bv_name</parameter>. Oracle does not use question
marks for placeholders.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>variable</parameter></term>
<listitem>
<para>
The PHP variable to be associated with <parameter>bv_name</parameter>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>maxlength</parameter></term>
<listitem>
<para>
Sets the maximum length for the data. If you set it to -1, this
function will use the current length
of <parameter>variable</parameter> to set the maximum
length. In this case the <parameter>variable</parameter> must
exist and contain data
when <function>oci_bind_by_name</function> is called.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>type</parameter></term>
<listitem>
<para>
The datatype that Oracle will treat the data as. The
default <parameter>type</parameter> used
is <constant>SQLT_CHR</constant>. Oracle will convert the data
between this type and the database column (or PL/SQL variable
type), when possible.
</para>
<para>
If you need to bind an abstract datatype (LOB/ROWID/BFILE) you
need to allocate it first using the
<function>oci_new_descriptor</function> function. The
<parameter>length</parameter> is not used for abstract datatypes
and should be set to -1.
</para>
<para>
Possible values for <parameter>type</parameter> are:
<itemizedlist>
<listitem>
<para>
<constant>SQLT_BFILEE</constant> or <constant>OCI_B_BFILE</constant>
<!-- really only single E --> - for BFILEs;
</para>
</listitem>
<listitem>
<para>
<constant>SQLT_CFILEE</constant> or <constant>OCI_B_CFILEE</constant>
- for CFILEs;
</para>
</listitem>
<listitem>
<para>
<constant>SQLT_CLOB</constant> or <constant>OCI_B_CLOB</constant>
- for CLOBs;
</para>
</listitem>
<listitem>
<para>
<constant>SQLT_BLOB</constant> or <constant>OCI_B_BLOB</constant>
- for BLOBs;
</para>
</listitem>
<listitem>
<para>
<constant>SQLT_RDD</constant> or <constant>OCI_B_ROWID</constant>
- for ROWIDs;
</para>
</listitem>
<listitem>
<para>
<constant>SQLT_NTY</constant> or <constant>OCI_B_NTY</constant>
- for named datatypes;
</para>
</listitem>
<listitem>
<para>
<constant>SQLT_INT</constant> or <constant>OCI_B_INT</constant> - for integers;
</para>
</listitem>
<listitem>
<para>
<constant>SQLT_CHR</constant> - for VARCHARs;
</para>
</listitem>
<listitem>
<para>
<constant>SQLT_BIN</constant> or <constant>OCI_B_BIN</constant>
- for RAW columns;
</para>
</listitem>
<listitem>
<para>
<constant>SQLT_LNG</constant> - for LONG columns;
</para>
</listitem>
<listitem>
<para>
<constant>SQLT_LBI</constant> - for LONG RAW columns;
</para>
</listitem>
<listitem>
<para>
<constant>SQLT_RSET</constant> - for cursors created
with <function>oci_new_cursor</function>.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</refsect1>
<refsect1 role="returnvalues">
&reftitle.returnvalues;
<para>
&return.success;
</para>
</refsect1>
<refsect1 role="examples">
&reftitle.examples;
<para>
<example>
<title>Inserting data with <function>oci_bind_by_name</function></title>
<programlisting role="php">
<![CDATA[
<?php
// Create the table with:
// CREATE TABLE mytab (id NUMBER, text VARCHAR2(40));
$conn = oci_connect('hr', 'welcome', 'localhost/XE');
if (!$conn) {
$m = oci_error();
trigger_error(htmlentities($m['message']), E_USER_ERROR);
}
$stid = oci_parse($conn,"INSERT INTO mytab (id, text) VALUES(:id_bv, :text_bv)");
$id = 1;
$text = "Data to insert ";
oci_bind_by_name($stid, ":id_bv", $id);
oci_bind_by_name($stid, ":text_bv", $text);
oci_execute($stid);
// Table now contains: 1, 'Data to insert '
?>
]]>
</programlisting>
</example>
</para>
<para>
<example>
<title>Binding once for multiple executions</title>
<programlisting role="php">
<![CDATA[
<?php
// Create the table with:
// CREATE TABLE mytab (id NUMBER);
$conn = oci_connect('hr', 'welcome', 'localhost/XE');
if (!$conn) {
$m = oci_error();
trigger_error(htmlentities($m['message']), E_USER_ERROR);
}
$a = array(1,3,5,7,11); // data to insert
$stid = oci_parse($conn, 'INSERT INTO mytab (id) VALUES (:bv)');
oci_bind_by_name($stid, ':bv', $v, 20);
foreach ($a as $v) {
$r = oci_execute($stid, OCI_DEFAULT); // don't auto commit
}
oci_commit($conn); // commit everything at once
// Table contains five rows: 1, 3, 5, 7, 11
oci_free_statement($stid);
oci_close($conn);
?>
]]>
</programlisting>
</example>
</para>
<para>
<example>
<title>Binding with a <function>foreach</function> loop</title>
<programlisting role="php">
<![CDATA[
<?php
$conn = oci_connect('hr', 'welcome', 'localhost/XE');
if (!$conn) {
$m = oci_error();
trigger_error(htmlentities($m['message']), E_USER_ERROR);
}
$sql = 'SELECT * FROM departments WHERE department_name = :dname AND location_id = :loc';
$stid = oci_parse($conn, $sql);
$ba = array(':dname' => 'IT Support', ':loc' => 1700);
foreach ($ba as $key => $val) {
// oci_bind_by_name($stid, $key, $val) does not work
// because it binds each placeholder to the same location: $val
// instead use the actual location of the data: $ba[$key]
oci_bind_by_name($stid, $key, $ba[$key]);
}
oci_execute($stid);
$row = oci_fetch_array($stid, OCI_ASSOC+OCI_RETURN_NULLS);
foreach ($row as $item) {
print $item."<br>\n";
}
oci_free_statement($stid);
oci_close($conn);
?>
]]>
</programlisting>
</example>
</para>
<para>
<example>
<title>Binding in a WHERE clause</title>
<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 employee_id = :eidbv';
$stid = oci_parse($conn, $sql);
$myeid = 101;
oci_bind_by_name($stid, ':eidbv', $myeid);
oci_execute($stid);
$row = oci_fetch_array($stid, OCI_ASSOC);
echo $row['LAST_NAME'] ."<br>\n";
// Output is
// Kochhar
oci_free_statement($stid);
oci_close($conn);
?>
]]>
</programlisting>
</example>
</para>
<para>
<example>
<title>Binding with a LIKE clause</title>
<programlisting role="php">
<![CDATA[
<?php
$conn = oci_connect('hr', 'welcome', 'localhost/XE');
if (!$conn) {
$m = oci_error();
trigger_error(htmlentities($m['message']), E_USER_ERROR);
}
// Find all cities that begin with 'South'
$stid = oci_parse($conn, "SELECT city FROM locations WHERE city LIKE :bv");
$city = 'South%'; // '%' is a wildcard in SQL
oci_bind_by_name($stid, ":bv", $city);
oci_execute($stid);
oci_fetch_all($stid, $res);
foreach ($res['CITY'] as $c) {
print $c . "<br>\n";
}
// Output is
// South Brunswick
// South San Francisco
// Southlake
oci_free_statement($stid);
oci_close($conn);
?>
]]>
</programlisting>
</example>
</para>
<para>
<example>
<title>Binding with REGEXP_LIKE</title>
<programlisting role="php">
<![CDATA[
<?php
$conn = oci_connect('hr', 'welcome', 'localhost/XE');
if (!$conn) {
$m = oci_error();
trigger_error(htmlentities($m['message']), E_USER_ERROR);
}
// Find all cities that contain 'ing'
$stid = oci_parse($conn, "SELECT city FROM locations WHERE REGEXP_LIKE(city, :bv)");
$city = '.*ing.*';
oci_bind_by_name($stid, ":bv", $city);
oci_execute($stid);
oci_fetch_all($stid, $res);
foreach ($res['CITY'] as $c) {
print $c . "<br>\n";
}
// Output is
// Beijing
// Singapore
oci_free_statement($stid);
oci_close($conn);
?>
]]>
</programlisting>
</example>
</para>
<para>
For a small, fixed number of IN clause conditions, use individual
bind variables. Values unknown at run time can be set to NULL.
This allows a single statement to be used by all application
users, maximizing Oracle DB cache efficiency.
</para>
<para>
<example>
<title>Binding Multiple Values in an IN Clause</title>
<programlisting role="php">
<![CDATA[
<?php
$conn = oci_connect('hr', 'welcome', 'localhost/XE');
if (!$conn) {
$m = oci_error();
trigger_error(htmlentities($m['message']), E_USER_ERROR);
}
$sql = 'SELECT last_name FROM employees WHERE employee_id in (:e1, :e2, :e3)';
$stid = oci_parse($conn, $sql);
$mye1 = 103;
$mye2 = 104;
$mye3 = NULL; // pretend we were not given this value
oci_bind_by_name($stid, ':e1', $mye1);
oci_bind_by_name($stid, ':e2', $mye2);
oci_bind_by_name($stid, ':e3', $mye3);
oci_execute($stid);
oci_fetch_all($stid, $res);
foreach ($res['LAST_NAME'] as $name) {
print $name ."<br>\n";
}
// Output is
// Ernst
// Hunold
oci_free_statement($stid);
oci_close($conn);
?>
]]>
</programlisting>
</example>
</para>
<para>
<example>
<title>Binding a ROWID returned by a query</title>
<programlisting role="php">
<![CDATA[
<?php
// Create the table with:
// CREATE TABLE mytab (id NUMBER, salary NUMBER, name VARCHAR2(40));
// INSERT INTO mytab (id, salary, name) VALUES (1, 100, 'Chris');
// COMMIT;
$conn = oci_connect('hr', 'welcome', 'localhost/XE');
if (!$conn) {
$m = oci_error();
trigger_error(htmlentities($m['message']), E_USER_ERROR);
}
$stid = oci_parse($conn, 'SELECT ROWID, name FROM mytab WHERE id = :id_bv FOR UPDATE');
$id = 1;
oci_bind_by_name($stid, ':id_bv', $id);
oci_execute($stid);
$row = oci_fetch_array($stid, OCI_ASSOC+OCI_RETURN_NULLS);
$rid = $row['ROWID'];
$name = $row['NAME'];
// Change name to upper case & save the changes
$name = strtoupper($name);
$stid = oci_parse($conn, 'UPDATE mytab SET name = :n_bv WHERE ROWID = :r_bv');
oci_bind_by_name($stid, ':n_bv', $name);
oci_bind_by_name($stid, ':r_bv', $rid, -1, OCI_B_ROWID);
oci_execute($stid);
// The table now contains 1, 100, CHRIS
oci_free_statement($stid);
oci_close($conn);
?>
]]>
</programlisting>
</example>
</para>
<para>
<example>
<title>Binding a ROWID on INSERT</title>
<programlisting role="php">
<![CDATA[
<?php
// This example inserts an id & name, and then updates the salary
// Create the table with:
// CREATE TABLE mytab (id NUMBER, salary NUMBER, name VARCHAR2(40));
//
// Based on original ROWID example by thies at thieso dot net (980221)
$conn = oci_connect('hr', 'welcome', 'localhost/XE');
if (!$conn) {
$m = oci_error();
trigger_error(htmlentities($m['message']), E_USER_ERROR);
}
$sql = "INSERT INTO mytab (id, name) VALUES(:id_bv, :name_bv)
RETURNING ROWID INTO :rid";
$ins_stid = oci_parse($conn, $sql);
$rowid = oci_new_descriptor($conn, OCI_D_ROWID);
oci_bind_by_name($ins_stid, ":id_bv", $id, 10);
oci_bind_by_name($ins_stid, ":name_bv", $name, 32);
oci_bind_by_name($ins_stid, ":rid", $rowid, -1, OCI_B_ROWID);
$sql = "UPDATE mytab SET salary = :salary WHERE ROWID = :rid";
$upd_stid = oci_parse($conn, $sql);
oci_bind_by_name($upd_stid, ":rid", $rowid, -1, OCI_B_ROWID);
oci_bind_by_name($upd_stid, ":salary", $salary, 32);
// ids and names to insert
$data = array(1111 => "Larry",
2222 => "Bill",
3333 => "Jim");
// Salary of each person
$salary = 10000;
// Insert and immediately update each row
foreach ($data as $id => $name) {
oci_execute($ins_stid);
oci_execute($upd_stid);
}
$rowid->free();
oci_free_statement($upd_stid);
oci_free_statement($ins_stid);
// Show the new rows
$stid = oci_parse($conn, "SELECT * FROM mytab");
oci_execute($stid);
while ($row = oci_fetch_array($stid, OCI_ASSOC+OCI_RETURN_NULLS)) {
var_dump($row);
}
oci_free_statement($stid);
oci_close($conn);
?>
]]>
</programlisting>
</example>
</para>
<para>
<example>
<title>Binding for a PL/SQL stored function</title>
<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']), E_USER_ERROR);
}
$p = 8;
$stid = oci_parse($conn, 'begin :r := myfunc(:p); end;');
oci_bind_by_name($stid, ':p', $p);
// The return value is an OUT bind. The default type will be a string
// type so binding a length 40 means that at most 40 digits will be
// returned.
oci_bind_by_name($stid, ':r', $r, 40);
oci_execute($stid);
print "$r\n"; // prints 24
oci_free_statement($stid);
oci_close($conn);
?>
]]>
</programlisting>
</example>
</para>
<para>
<example>
<title>Binding parameters for a PL/SQL stored procedure</title>
<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']), E_USER_ERROR);
}
$p1 = 8;
$stid = oci_parse($conn, 'begin myproc(:p1, :p2); end;');
oci_bind_by_name($stid, ':p1', $p1);
// The second procedure parameter is an OUT bind. The default type
// will be a string type so binding a length 40 means that at most 40
// digits will be returned.
oci_bind_by_name($stid, ':p2', $p2, 40);
oci_execute($stid);
print "$p2\n"; // prints 16
oci_free_statement($stid);
oci_close($conn);
?>
]]>
</programlisting>
</example>
</para>
<para>
<example>
<title>Binding a CLOB column</title>
<programlisting role="php">
<![CDATA[
<?php
// Before running, create the table:
// CREATE TABLE mytab (mykey NUMBER, myclob CLOB);
$conn = oci_connect('hr', 'welcome', 'localhost/XE');
if (!$conn) {
$e = oci_error();
trigger_error(htmlentities($e['message']), E_USER_ERROR);
}
$mykey = 12343; // arbitrary key for this example;
$sql = "INSERT INTO mytab (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_DEFAULT);
$clob->save("A very long string");
oci_commit($conn);
// Fetching CLOB data
$query = 'SELECT myclob FROM mytab 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)) {
$result = $row['MYCLOB']->load();
print '<tr><td>'.$result.'</td></tr>';
}
print '</table>';
?>
]]>
</programlisting>
</example>
</para>
</refsect1>
<refsect1 role="returnvalues">
&reftitle.returnvalues;
<para>
&return.success;
</para>
</refsect1>
<refsect1 role="notes">
&reftitle.notes;
<warning>
<para>
Do not use <link
linkend="ini.magic-quotes-gpc">magic_quotes_gpc</link> or
<function>addslashes</function>
and <function>oci_bind_by_name</function> simultaneously as no
quoting is needed. Any magically applied quotes will be written
into your database because <function>oci_bind_by_name</function>
inserts data verbatim and does not remove quotes or escape
characters.
</para>
</warning>
<note>
<para>
If you bind a string to a <literal>CHAR</literal> column in
a <literal>WHERE</literal> clause, remember that Oracle uses
blank-padded comparison semantics for <literal>CHAR</literal>
columns. Your PHP variable should be blank padded to the same
width as the column for the <literal>WHERE</literal> clause to
succeed.
</para>
</note>
<note>
<para>
The PHP <parameter>variable</parameter> argument is a reference. Some
forms of loops do not work as expected:
</para>
<informalexample>
<programlisting role="php">
<![CDATA[
<?php
foreach ($myarray as $key => $value) {
oci_bind_by_name($stid, $key, $value);
}
?>
]]>
</programlisting>
</informalexample>
<para>
This binds each key to the location of $value, so all bound
variables end up pointing to the last loop iteration's
value. Instead use the following:
</para>
<informalexample>
<programlisting role="php">
<![CDATA[
<?php
foreach ($myarray as $key => $value) {
oci_bind_by_name($stid, $key, $myarray[$key]);
}
?>
]]>
</programlisting>
</informalexample>
</note>
<note>
<para>
In PHP versions before 5.0.0 you must
use <function>ocibindbyname</function>
instead. &oci.name.compat.note;
</para>
</note>
</refsect1>
<refsect1 role="seealso">
&reftitle.seealso;
<para>
<simplelist>
<member><function>oci_bind_array_by_name</function></member>
<member><function>oci_parse</function></member>
</simplelist>
</para>
</refsect1>
</refentry>
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