<?xml version='1.0' encoding='iso-8859-1'?>
<!-- $Revision: 1.49 $ -->
<!-- Purpose: database.abstract -->
<!-- Membership: pecl, bundled -->
<reference id="ref.pdo">
<title>PDO Functions</title>
<titleabbrev>PDO</titleabbrev>
<partintro>
<section id="pdo.intro">
&reftitle.intro;
<para>
The PHP Data Objects (PDO) extension defines a lightweight, consistent interface
for accessing databases in PHP. Each database driver that
implements the PDO interface can expose database-specific
features as regular extension functions. Note that you cannot
perform any database functions using the PDO extension by
itself; you must use a <link linkend="pdo.drivers">database-specific
PDO driver</link> to access a database server.
</para>
<para>
PDO provides a <emphasis>data-access</emphasis> abstraction layer, which
means that, regardless of which database you're using, you use the same
functions to issue queries and fetch data. PDO does
<emphasis>not</emphasis> provide a <emphasis>database</emphasis>
abstraction; it doesn't rewrite SQL or emulate missing features. You
should use a full-blown abstraction layer if you need that facility.
</para>
<para>
PDO ships with PHP 5.1, and is available as a PECL extension for PHP 5.0;
PDO requires the new OO features in the core of PHP 5, and so will not
run with earlier versions of PHP.
</para>
</section>
<section id="pdo.installation">
&reftitle.install;
<procedure id='pdo.install.unix51up'>
<title>PHP 5.1 and up on Unix systems</title>
<step>
<para>
If you're running a PHP 5.1 release, PDO is included in the distribution;
it will be automatically enabled when you run configure. It is
recommended that you build PDO as a shared extension, as this will allow
you to take advantage of updates that are made available via PECL. The
recommended configure line for building PHP with PDO support should
enable zlib support (for the pear installer) as well. You may also need
to enable the PDO driver for your database of choice; consult the
documentation for <link linkend="pdo.drivers">database-specific
PDO drivers</link> to find out more about that, but note that if you
build PDO as a shared extension, you must build the PDO drivers as
shared extensions.
<screen>
<![CDATA[
./configure --with-zlib --enable-pdo=shared
]]>
</screen>
</para>
</step>
<step>
<para>
After installing PDO as a shared module, you must edit your php.ini file
so that the PDO extension will be loaded automatically when PHP runs.
You will also need to enable any database specific drivers there too;
make sure that they are listed after the pdo.so line, as PDO must be
initialized before the database-specific extensions can be loaded.
If you built PDO and the database-specific extensions statically, you
can skip this step.
<screen>
<![CDATA[
extension=pdo.so
]]>
</screen>
</para>
</step>
<step>
<para>
Having PDO as a shared module will allow you to run <command>pear
upgrade pdo</command> as new versions of PDO are published, without
forcing you to rebuild the whole of PHP. Note that if you do this, you
also need to upgrade your database specific PDO drivers at the same
time.
</para>
</step>
</procedure>
<procedure id='pdo.install.pecl'>
<title>PHP 5.0 and up on Unix systems</title>
<step>
<para>
PDO is available as a PECL extension from
<ulink url='&url.pecl.package;pdo'>&url.pecl.package;pdo</ulink>.
Installation can be performed via the <command>pear</command> tool; this
is enabled by default when you configure PHP. You should ensure that
PHP was configured --with-zlib in order for
<command>pear</command> to be able to handle the compressed package
files.
</para>
</step>
<step>
<para>
Run the following command to download, build, and install the
latest stable version of PDO:
<screen>
<![CDATA[
pear install pdo
]]>
</screen>
</para>
</step>
<step>
<para>
If PDO is still in beta (and at the time of writing, it is), you will
need to tell the pear tool that it's ok to fetch the beta package.
Instead of running the command above, run the following:
<screen>
<![CDATA[
pear install pdo-beta
]]>
</screen>
</para>
</step>
<step>
<para>
The <command>pear</command> command automatically installs the
PDO module into your PHP extensions directory. To enable the
PDO extension on Linux or Unix operating systems, you must add
the following line to &php.ini;:
<screen>
<![CDATA[
extension=pdo.so
]]>
</screen>
</para>
<para>
For more information about building PECL packages, consult the
<link linkend="install.pecl">PECL installation</link> section of the manual.
</para>
</step>
</procedure>
<procedure id='pdo.install.win32php51'>
<title>Windows users running PHP 5.1 and up</title>
<step>
<para>
PDO and all the major drivers ship with PHP as shared extensions, and
simply need to be activated by editing the &php.ini; file:
<screen>
<![CDATA[
extension=php_pdo.dll
]]>
</screen>
</para>
</step>
<step>
<para>
Next, choose the other database-specific DLL files and either use
<function>dl</function> to load them at runtime, or enable them in
&php.ini; below <filename>php_pdo.dll</filename>. For example:
<screen>
<![CDATA[
extension=php_pdo.dll
extension=php_pdo_firebird.dll
extension=php_pdo_informix.dll
extension=php_pdo_mssql.dll
extension=php_pdo_mysql.dll
extension=php_pdo_oci.dll
extension=php_pdo_oci8.dll
extension=php_pdo_odbc.dll
extension=php_pdo_pgsql.dll
extension=php_pdo_sqlite.dll
]]>
</screen>
</para>
<para>
These DLLs should exist in the system's
<link linkend="ini.extension-dir">extension_dir</link>.
Note that <link linkend="ref.pdo-informix">PDO_INFORMIX</link>
is only available as a PECL extension.
</para>
</step>
</procedure>
</section>
&reference.pdo.ini;
<section id="pdo.drivers">
<title>PDO Drivers</title>
<para>
The following drivers currently implement the PDO interface:
<informaltable>
<tgroup cols='2'>
<thead>
<row>
<entry>Driver name</entry>
<entry>Supported databases</entry>
</row>
</thead>
<tbody>
<row>
<entry><link linkend="ref.pdo-dblib">PDO_DBLIB</link></entry>
<entry>FreeTDS / Microsoft SQL Server / Sybase</entry>
</row>
<row>
<entry><link linkend="ref.pdo-firebird">PDO_FIREBIRD</link></entry>
<entry>Firebird/Interbase 6</entry>
</row>
<row>
<entry><link linkend="ref.pdo-informix">PDO_INFORMIX</link></entry>
<entry>IBM Informix Dynamic Server</entry>
</row>
<row>
<entry><link linkend="ref.pdo-mysql">PDO_MYSQL</link></entry>
<entry>MySQL 3.x/4.x</entry>
</row>
<row>
<entry><link linkend="ref.pdo-oci">PDO_OCI</link></entry>
<entry>Oracle Call Interface</entry>
</row>
<row>
<entry><link linkend="ref.pdo-odbc">PDO_ODBC</link></entry>
<entry>ODBC v3 (IBM DB2, unixODBC and win32 ODBC)</entry>
</row>
<row>
<entry><link linkend="ref.pdo-pgsql">PDO_PGSQL</link></entry>
<entry>PostgreSQL</entry>
</row>
<row>
<entry><link linkend="ref.pdo-sqlite">PDO_SQLITE</link></entry>
<entry>SQLite 3 and SQLite 2</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</para>
</section>
<section id='pdo.connections'>
<title>Connections and Connection management</title>
<para>
Connections are established by creating instances of the PDO base class.
It doesn't matter which driver you want to use; you always use the PDO
class name. The constructor accepts parameters for specifying the
database source (known as the DSN) and optionally for the username and
password (if any).
</para>
<para>
<example><title>Connecting to MySQL</title>
<programlisting role='php'>
<![CDATA[
<?php
$dbh = new PDO('mysql:host=localhost;dbname=test', $user, $pass);
?>
]]>
</programlisting>
</example>
</para>
<para>
If there are any connection errors, a <literal>PDOException</literal>
object will be thrown. You may catch the exception if you want to handle
the error condition, or you may opt to leave it for an application
global exception handler that you set up via
<function>set_exception_handler</function>.
</para>
<para>
<example><title>Handling connection errors</title>
<programlisting role='php'>
<![CDATA[
<?php
try {
$dbh = new PDO('mysql:host=localhost;dbname=test', $user, $pass);
foreach ($dbh->query('SELECT * from FOO') as $row) {
print_r($row);
}
$dbh = null;
} catch (PDOException $e) {
print "Error!: " . $e->getMessage() . "<br/>";
die();
}
?>
]]>
</programlisting>
</example>
</para>
<warning>
<para>
If your application does not catch the exception thrown from the PDO
constructor, the default action taken by the zend engine is to terminate
the script and display a back trace. This back trace will likely reveal
the full database connection details, including the username and
password. It is your responsibility to catch this exception, either
explicitly (via a <literal>catch</literal> statement) or implicitly via
<function>set_exception_handler</function>.
</para>
</warning>
<para>
Upon successful connection to the database, an instance of the PDO class
is returned to your script. The connection remains active for the
lifetime of that PDO object. To close the connection, you need to
destroy the object by ensuring that all remaining references to it are
deleted--you do this by assigning &null; to the variable that holds the
object. If you don't do this explicitly, PHP will automatically close
the connection when your script ends.
</para>
<para>
<example><title>Closing a connection</title>
<programlisting role='php'>
<![CDATA[
<?php
$dbh = new PDO('mysql:host=localhost;dbname=test', $user, $pass);
// use the connection here
// and now we're done; close it
$dbh = null;
?>
]]>
</programlisting>
</example>
</para>
<para>
Many web applications will benefit from making persistent connections to
database servers. Persistent connections are not closed at the end of the
script, but are cached and re-used when another script requests a
connection using the same credentials. The persistent connection cache
allows you to avoid the overhead of establishing a new connection every
time a script needs to talk to a database, resulting in a faster web
application.
</para>
<para>
<example><title>Persistent connections</title>
<programlisting role='php'>
<![CDATA[
<?php
$dbh = new PDO('mysql:host=localhost;dbname=test', $user, $pass, array(
PDO::ATTR_PERSISTENT => true
));
?>
]]>
</programlisting>
</example>
</para>
<note>
<para>
If you're using the PDO ODBC driver and your ODBC libraries support ODBC
Connection Pooling (unixODBC and Windows are two that do; there may be
more), then it's recommended that you don't use persistent PDO
connections, and instead leave the connection caching to the ODBC
Connection Pooling layer. The ODBC Connection Pool is shared with other
modules in the process; if PDO is told to cache the connection, then
that connection would never be returned to the ODBC connection pool,
resulting in additional connections being created to service those other
modules.
</para>
</note>
</section>
<section id='pdo.transactions'>
<title>Transactions and auto-commit</title>
<para>
Now that you're connected via PDO, you must understand how PDO
manages transactions before you start issuing queries. If you've never
encountered transactions before, they offer 4 major features: Atomicity,
Consistency, Isolation and Durability (ACID). In layman's terms, any work
carried out in a transaction, even if it is carried out in stages, is
guaranteed to be applied to the database safely, and without interference
from other connections, when it is committed. Transactional work can also
be automatically undone at your request (provided you haven't already
committed it), which makes error handling in your scripts easier.
</para>
<para>
Transactions are typically implemented by "saving-up" your batch of
changes to be applied all at once; this has the nice side effect of
drastically improving the efficiency of those updates. In other words,
transactions can make your scripts faster and potentially more robust
(you still need to use them correctly to reap that benefit).
</para>
<para>
Unfortunately, not every database supports transactions, so PDO needs to
run in what is known as "auto-commit" mode when you first open the
connection. Auto-commit mode means that every query that you run has its
own implicit transaction, if the database supports it, or no transaction
if the database doesn't support transactions. If you need a transaction,
you must use the <function>PDO::beginTransaction</function> method to
initiate one. If the underlying driver does not support transactions, a
PDOException will be thrown (regardless of your error handling settings:
this is always a serious error condition). Once you are in a transaction,
you may use <function>PDO::commit</function> or
<function>PDO::rollBack</function> to finish it, depending on the success
of the code you run during the transaction.
</para>
<para>
When the script ends or when a connection is about to be closed, if you
have an outstanding transaction, PDO will automatically roll it back.
This is a safety measure to help avoid inconsistency in the cases where
the script terminates unexpectedly--if you didn't explicitly commit the
transaction, then it is assumed that something went awry, so the rollback
is performed for the safety of your data.
</para>
<warning>
<para>
The automatic rollback only happens if you initiate the transaction via
<function>PDO::beginTransaction</function>. If you manually issue a
query that begins a transaction PDO has no way of knowing about it and
thus cannot roll it back if something bad happens.
</para>
</warning>
<para>
<example><title>Executing a batch in a transaction</title>
<para>
In the following sample, let's assume that we are creating a set of
entries for a new employee, who has been assigned an ID number of 23.
In addition to entering the basic data for that person, we also need to
record their salary. It's pretty simple to make two separate updates,
but by enclosing them within the
<function>PDO::beginTransaction</function> and
<function>PDO::commit</function> calls, we are guaranteeing that no one
else will be able to see those changes until they are complete. If
something goes wrong, the catch block rolls back all changes made
since the transaction was started, and then prints out an error
message.
</para>
<programlisting role='php'>
<![CDATA[
<?php
try {
$dbh = new PDO('odbc:SAMPLE', 'db2inst1', 'ibmdb2',
array(PDO::ATTR_PERSISTENT => true));
echo "Connected\n";
$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$dbh->beginTransaction();
$dbh->exec("insert into staff (id, first, last) values (23, 'Joe', 'Bloggs')");
$dbh->exec("insert into salarychange (id, amount, changedate)
values (23, 50000, NOW())");
$dbh->commit();
} catch (Exception $e) {
$dbh->rollBack();
echo "Failed: " . $e->getMessage();
}
?>
]]>
</programlisting>
</example>
</para>
<para>
You're not limited to making updates in a transaction; you can also issue
complex queries to extract data, and possibly use that information to
build up more updates and queries; while the transaction is active, you
are guaranteed that no one else can make changes while you are in the
middle of your work. In truth, this isn't 100% correct, but it is a
good-enough introduction, if you've never heard of transactions before.
</para>
</section>
<section id='pdo.prepared-statements'>
<title>Prepared statements and stored procedures</title>
<para>
Many of the more mature databases support the concept of prepared
statements. What are they? You can think of them as a kind of compiled
template for the SQL that you want to run, that can be customized using
variable parameters. Prepared statements offer two major benefits:
</para>
<itemizedlist>
<listitem>
<simpara>
The query only needs to be parsed (or prepared) once, but can be
executed multiple times with the same or different parameters. When the
query is prepared, the database will analyze, compile and optimize it's
plan for executing the query. For complex queries this process can take
up enough time that it will noticeably slow down your application if you
need to repeat the same query many times with different parameters. By
using a prepared statement you avoid repeating the
analyze/compile/optimize cycle. In short, prepared statements use fewer
resources and thus run faster.
</simpara>
</listitem>
<listitem>
<simpara>
The parameters to prepared statements don't need to be quoted; the
driver handles it for you. If your application exclusively uses
prepared statements, you can be sure that no SQL injection will occur.
(However, if you're still building up other parts of the query based on
untrusted input, you're still at risk).
</simpara>
</listitem>
</itemizedlist>
<para>
Prepared statements are so useful that they are the only feature that PDO
will emulate for drivers that don't support them. This ensures that you
will be able to use the same data access paradigm regardless of the
capabilities of the database.
</para>
<para>
<example><title>Repeated inserts using prepared statements</title>
<simpara>
This example performs an INSERT query by substituting a <literal>name</literal>
and a <literal>value</literal> for the named placeholders.
</simpara>
<programlisting role='php'>
<![CDATA[
<?php
$stmt = $dbh->prepare("INSERT INTO REGISTRY (name, value) VALUES (:name, :value)");
$stmt->bindParam(':name', $name);
$stmt->bindParam(':value', $value);
// insert one row
$name = 'one';
$value = 1;
$stmt->execute();
// insert another row with different values
$name = 'two';
$value = 2;
$stmt->execute();
?>
]]>
</programlisting>
</example>
</para>
<para>
<example><title>Repeated inserts using prepared statements</title>
<simpara>
This example performs an INSERT query by substituting a <literal>name</literal>
and a <literal>value</literal> for the positional <literal>?</literal> placeholders.
</simpara>
<programlisting role='php'>
<![CDATA[
<?php
$stmt = $dbh->prepare("INSERT INTO REGISTRY (name, value) VALUES (?, ?)");
$stmt->bindParam(1, $name);
$stmt->bindParam(2, $value);
// insert one row
$name = 'one';
$value = 1;
$stmt->execute();
// insert another row with different values
$name = 'two';
$value = 2;
$stmt->execute();
?>
]]>
</programlisting>
</example>
</para>
<para>
<example><title>Fetching data using prepared statements</title>
<simpara>
This example fetches data based on a key value supplied by a form.
The user input is automatically quoted, so there is no risk of a
SQL injection attack.
</simpara>
<programlisting role='php'>
<![CDATA[
<?php
$stmt = $dbh->prepare("SELECT * FROM REGISTRY where name = ?");
if ($stmt->execute(array($_GET['name']))) {
while ($row = $stmt->fetch()) {
print_r($row);
}
}
?>
]]>
</programlisting>
</example>
</para>
<para>
If the database driver supports it, you may also bind parameters for
output as well as input. Output parameters are typically used to retrieve
values from stored procedures. Output parameters are slightly more complex
to use than input parameters, in that you must know how large a given
parameter might be when you bind it. If the value turns out to be larger
than the size you suggested, an error is raised.
</para>
<para>
<example><title>Calling a stored procedure with an output parameter</title>
<programlisting role='php'>
<![CDATA[
<?php
$stmt = $dbh->prepare("CALL sp_returns_string(?)");
$stmt->bindParam(1, $return_value, PDO::PARAM_STR, 4000);
// call the stored procedure
$stmt->execute();
print "procedure returned $return_value\n";
?>
]]>
</programlisting>
</example>
</para>
<para>
You may also specify parameters that hold values both input and output;
the syntax is similar to output parameters. In this next example, the
string 'hello' is passed into the stored procedure, and when it returns,
hello is replaced with the return value of the procedure.
</para>
<para>
<example><title>Calling a stored procedure with an input/output parameter</title>
<programlisting role='php'>
<![CDATA[
<?php
$stmt = $dbh->prepare("CALL sp_takes_string_returns_string(?)");
$value = 'hello';
$stmt->bindParam(1, $value, PDO::PARAM_STR|PDO::PARAM_INPUT_OUTPUT, 4000);
// call the stored procedure
$stmt->execute();
print "procedure returned $value\n";
?>
]]>
</programlisting>
</example>
</para>
</section>
<section id='pdo.error-handling'>
<title>Errors and error handling</title>
<para>
PDO offers you a choice of 3 different error handling strategies, to fit
your style of application development.
</para>
<itemizedlist>
<listitem>
<para>
<constant>PDO::ERRMODE_SILENT</constant>
</para>
<para>
This is the default mode. PDO will simply set the error code for you
to inspect using the <function>PDO::errorCode</function> and
<function>PDO::errorInfo</function> methods on both the
statement and database objects; if the error resulted from a call on a
statement object, you would invoke the
<function>PDOStatement::errorCode</function> or
<function>PDOStatement::errorInfo</function>
method on that object. If the error resulted from a call on the
database object, you would invoke those methods on the database object
instead.
</para>
</listitem>
<listitem>
<para>
<constant>PDO::ERRMODE_WARNING</constant>
</para>
<para>
In addition to setting the error code, PDO will emit a traditional
E_WARNING message. This setting is useful during debugging/testing, if
you just want to see what problems occurred without interrupting the
flow of the application.
</para>
</listitem>
<listitem>
<para>
<constant>PDO::ERRMODE_EXCEPTION</constant>
</para>
<para>
In addition to setting the error code, PDO will throw a
<classname>PDOException</classname>
and set its properties to reflect the error code and error
information. This setting is also useful during debugging, as it will
effectively "blow up" the script at the point of the error, very
quickly pointing a finger at potential problem areas in your code
(remember: transactions are automatically rolled back if the exception
causes the script to terminate).
</para>
<para>
Exception mode is also useful because you can structure your error
handling more clearly than with traditional PHP-style warnings, and
with less code/nesting than by running in silent mode and explicitly
checking the return value of each database call.
</para>
<para>
See <link linkend='language.exceptions'>Exceptions</link> for more
information about Exceptions in PHP.
</para>
</listitem>
</itemizedlist>
<para>
PDO standardizes on using SQL-92 SQLSTATE error code strings; individual
PDO drivers are responsible for mapping their native codes to the
appropriate SQLSTATE codes. The <function>PDO::errorCode</function>
method returns a single SQLSTATE code. If you need more specific
information about an error, PDO also offers an
<function>PDO::errorInfo</function> method which returns an array
containing the SQLSTATE code, the driver specific error code and driver
specific error string.
</para>
</section>
<section id='pdo.lobs'>
<title>Large Objects (LOBs)</title>
<para>
At some point in your application, you might find that you need to store
"large" data in your database. Large typically means "around 4kb or
more", although some databases can happily handle up to 32kb before data becomes
"large". Large objects can be either textual or binary in nature. PDO
allows you to work with this large data type by using the
<constant>PDO::PARAM_LOB</constant>
type code in your <function>PDOStatement::bindParam</function> or
<function>PDOStatement::bindColumn</function> calls.
<constant>PDO::PARAM_LOB</constant> tells
PDO to map the data as a stream, so that you can manipulate it using the
<link linkend='ref.stream'>PHP Streams API</link>.
</para>
<para>
</para>
<para>
<example><title>Displaying an image from a database</title>
<para>
This example binds the LOB into the variable named $lob and then sends
it to the browser using <function>fpassthru</function>. Since the LOB
is represented as a stream, functions such as
<function>fgets</function>, <function>fread</function> and
<function>stream_get_contents</function> can be used on it.
</para>
<programlisting role='php'>
<![CDATA[
<?php
$db = new PDO('odbc:SAMPLE', 'db2inst1', 'ibmdb2');
$stmt = $db->prepare("select contenttype, imagedata from images where id=?");
$stmt->execute(array($_GET['id']));
$stmt->bindColumn(1, $type, PDO::PARAM_STR, 256);
$stmt->bindColumn(2, $lob, PDO::PARAM_LOB);
$stmt->fetch(PDO::FETCH_BOUND);
header("Content-Type: $type");
fpassthru($lob);
?>
]]>
</programlisting>
</example>
</para>
<para>
<example><title>Inserting an image into a database</title>
<para>
This example opens up a file and passes the file handle to PDO to insert
it as a LOB. PDO will do its best to get the contents of the file up
to the database in the most efficient manner possible.
</para>
<programlisting role='php'>
<![CDATA[
<?php
$db = new PDO('odbc:SAMPLE', 'db2inst1', 'ibmdb2');
$stmt = $db->prepare("insert into images (id, contenttype, imagedata) values (?, ?, ?)");
$id = get_new_id(); // some function to allocate a new ID
// assume that we are running as part of a file upload form
// You can find more information in the PHP documentation
$fp = fopen($_FILES['file']['tmp_name'], 'rb');
$stmt->bindParam(1, $id);
$stmt->bindParam(2, $_FILES['file']['type']);
$stmt->bindParam(3, $fp, PDO::PARAM_LOB);
$stmt->beginTransaction();
$stmt->execute();
$stmt->commit();
?>
]]>
</programlisting>
</example>
</para>
<para>
<example><title>Inserting an image into a database: Oracle</title>
<para>
Oracle requires a slightly different syntax for inserting a lob from a
file. It's also essential that you perform the insert under a
transaction, otherwise your newly inserted LOB will be committed with a
zero-length as part of the implicit commit that happens when the query
is executed:
</para>
<programlisting role='php'>
<![CDATA[
<?php
$db = new PDO('oci:', 'scott', 'tiger');
$stmt = $db->prepare("insert into images (id, contenttype, imagedata) " .
"VALUES (?, ?, EMPTY_BLOB()) RETURNING imagedata INTO ?");
$id = get_new_id(); // some function to allocate a new ID
// assume that we are running as part of a file upload form
// You can find more information in the PHP documentation
$fp = fopen($_FILES['file']['tmp_name'], 'rb');
$stmt->bindParam(1, $id);
$stmt->bindParam(2, $_FILES['file']['type']);
$stmt->bindParam(3, $fp, PDO::PARAM_LOB);
$stmt->beginTransaction();
$stmt->execute();
$stmt->commit();
?>
]]>
</programlisting>
</example>
</para>
</section>
<section id='pdo.classes'>
&reftitle.classes;
<section id='pdo.class.PDO'>
<title><classname>PDO</classname></title>
<para>
Represents a connection between PHP and a database server.
</para>
<section id='pdo.class.PDO.constructor'>
&reftitle.constructor;
<itemizedlist>
<listitem>
<para>
<link linkend='function.PDO-construct'>PDO</link> - constructs a new
PDO object
</para>
</listitem>
</itemizedlist>
</section>
<section id='pdo.class.PDO.methods'>
&reftitle.methods;
<itemizedlist>
<listitem>
<para>
<link linkend='function.PDO-beginTransaction'>beginTransaction</link>
- begins a transaction
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDO-commit'>commit</link>
- commits a transaction
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDO-errorCode'>errorCode</link>
- retrieves an error code, if any, from the database
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDO-errorInfo'>errorInfo</link>
- retrieves an array of error information, if any, from the
database
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDO-exec'>exec</link>
- issues an SQL statement and returns the number of affected rows
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDO-getAttribute'>getAttribute</link>
- retrieves a database connection attribute
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDO-lastInsertId'>lastInsertId</link>
- retrieves the value of the last row that was inserted into a table
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDO-prepare'>prepare</link>
- prepares an SQL statement for execution
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDO-query'>query</link>
- issues an SQL statement and returns a result set
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDO-quote'>quote</link>
- returns a quoted version of a string for use in SQL statements
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDO-rollBack'>rollBack</link>
- roll back a transaction
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDO-setAttribute'>setAttribute</link>
- sets a database connection attribute
</para>
</listitem>
</itemizedlist>
</section>
</section>
<section id='pdo.class.PDOStatement'>
<title><classname>PDOStatement</classname></title>
<para>
Represents a prepared statement and, after the statement is executed, an
associated result set.
</para>
<section id='pdo.class.Statement.methods'>
&reftitle.methods;
<itemizedlist>
<listitem>
<para>
<link linkend='function.PDOStatement-bindColumn'>bindColumn</link>
- binds a PHP variable to an output column in a result set
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDOStatement-bindParam'>bindParam</link>
- binds a PHP variable to a parameter in the prepared statement
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDOStatement-bindValue'>bindValue</link>
- binds a value to a parameter in the prepared statement
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDOStatement-closeCursor'>closeCursor</link>
- closes the cursor, allowing the statement to be executed again
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDOStatement-columnCount'>columnCount</link>
- returns the number of columns in the result set
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDOStatement-errorCode'>errorCode</link>
- retrieves an error code, if any, from the statement
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDOStatement-errorInfo'>errorInfo</link>
- retrieves an array of error information, if any, from the statement
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDOStatement-execute'>execute</link>
- executes a prepared statement
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDOStatement-fetch'>fetch</link>
- fetches a row from a result set
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDOStatement-fetchAll'>fetchAll</link>
- fetches an array containing all of the rows from a result set
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDOStatement-fetchColumn'>fetchColumn</link>
- returns the data from a single column in a result set
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDOStatement-getAttribute'>getAttribute</link>
- retrieves a PDOStatement attribute
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDOStatement-getColumnMeta'>getColumnMeta</link>
- retrieves metadata for a column in the result set
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDOStatement-nextRowset'>nextRowset</link>
- retrieves the next rowset (result set)
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDOStatement-rowCount'>rowCount</link>
- returns the number of rows that were affected by the execution of
an SQL statement
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDOStatement-setAttribute'>setAttribute</link>
- sets a PDOStatement attribute
</para>
</listitem>
<listitem>
<para>
<link linkend='function.PDOStatement-setFetchMode'>setFetchMode</link>
- sets the fetch mode for a PDOStatement
</para>
</listitem>
</itemizedlist>
</section>
</section>
<section id='pdo.class.PDOException'>
<title><classname>PDOException</classname></title>
<para>
Represents an error raised by PDO. You should not throw a
<classname>PDOException</classname> from your own code.
See <link linkend='language.exceptions'>Exceptions</link> for more
information about Exceptions in PHP.
</para>
<example>
<title>The PDOException class</title>
<programlisting role='php'>
<![CDATA[
<?php
class PDOException extends Exception
{
public $errorInfo = null; // corresponds to PDO::errorInfo()
// or PDOStatement::errorInfo()
protected $message; // textual error message
// use Exception::getMessage() to access it
protected $code; // SQLSTATE error code
// use Exception::getCode() to access it
}
?>
]]>
</programlisting>
</example>
</section>
</section>
&reference.pdo.constants;
</partintro>
&reference.pdo.functions;
</reference>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:t
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
indent-tabs-mode:nil
sgml-parent-document:nil
sgml-default-dtd-file:"../../../manual.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:nil
sgml-local-ecat-files:nil
End:
vim600: syn=xml fen fdm=syntax fdl=2 si
vim: et tw=78 syn=sgml
vi: ts=1 sw=1
-->