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<h1 class="refname">PDO::beginTransaction</h1>
<p class="verinfo">(PHP 5 >= 5.1.0, PECL pdo >= 0.1.0)</p><p class="refpurpose"><span class="refname">PDO::beginTransaction</span> — <span class="dc-title">
Initiates a transaction
</span></p>
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<div class="refsect1 description" id="refsect1-pdo.begintransaction-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="modifier">public</span> <span class="type">bool</span> <span class="methodname"><strong>PDO::beginTransaction</strong></span>
( <span class="methodparam">void</span>
)</div>
<p class="para rdfs-comment">
Turns off autocommit mode. While autocommit mode is turned off, changes
made to the database via the PDO object instance are not committed until
you end the transaction by calling <span class="function"><a href="pdo.commit.html" class="function">PDO::commit()</a></span>.
Calling <span class="function"><a href="pdo.rollback.html" class="function">PDO::rollBack()</a></span> will roll back all changes to
the database and return the connection to autocommit mode.
</p>
<p class="para">
Some databases, including MySQL, automatically issue an implicit
COMMIT when a database definition language (DDL) statement such as
DROP TABLE or CREATE TABLE is issued within a transaction. The implicit
COMMIT will prevent you from rolling back any other changes within the
transaction boundary.
</p>
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<div class="refsect1 returnvalues" id="refsect1-pdo.begintransaction-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns <strong><code>TRUE</code></strong> on success or <strong><code>FALSE</code></strong> on failure.
</p>
</div>
<div class="refsect1 examples" id="refsect1-pdo.begintransaction-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-915"><p><strong>Example #1 Roll back a transaction</strong></p>
<div class="example-contents"><p>
The following example begins a transaction and issues two statements
that modify the database before rolling back the changes. On MySQL,
however, the DROP TABLE statement automatically commits the
transaction so that none of the changes in the transaction are rolled
back.
</p></div>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">/* Begin a transaction, turning off autocommit */<br /></span><span style="color: #0000BB">$dbh</span><span style="color: #007700">-></span><span style="color: #0000BB">beginTransaction</span><span style="color: #007700">();<br /><br /></span><span style="color: #FF8000">/* Change the database schema and data */<br /></span><span style="color: #0000BB">$sth </span><span style="color: #007700">= </span><span style="color: #0000BB">$dbh</span><span style="color: #007700">-></span><span style="color: #0000BB">exec</span><span style="color: #007700">(</span><span style="color: #DD0000">"DROP TABLE fruit"</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$sth </span><span style="color: #007700">= </span><span style="color: #0000BB">$dbh</span><span style="color: #007700">-></span><span style="color: #0000BB">exec</span><span style="color: #007700">(</span><span style="color: #DD0000">"UPDATE dessert<br /> SET name = 'hamburger'"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/* Recognize mistake and roll back changes */<br /></span><span style="color: #0000BB">$dbh</span><span style="color: #007700">-></span><span style="color: #0000BB">rollBack</span><span style="color: #007700">();<br /><br /></span><span style="color: #FF8000">/* Database connection is now back in autocommit mode */<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
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</p>
</div>
<div class="refsect1 seealso" id="refsect1-pdo.begintransaction-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"> <span class="function"><a href="pdo.commit.html" class="function" rel="rdfs-seeAlso">PDO::commit()</a> - Commits a transaction</span></li>
<li class="member"> <span class="function"><a href="pdo.rollback.html" class="function" rel="rdfs-seeAlso">PDO::rollBack()</a> - Rolls back a transaction</span></li>
<li class="member"><a href="pdo.transactions.html" class="link">Transactions and auto-commit</a></li>
</ul>
</p>
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