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<h1 class="refname">mysql_fetch_field</h1>
<p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">mysql_fetch_field</span> — <span class="dc-title">Get column information from a result and return as an object</span></p>
</div>
<div id="function.mysql-fetch-field-refsynopsisdiv">
<div class="warning"><strong class="warning">Warning</strong>
<p class="para">This extension is deprecated as of PHP 5.5.0, and will be removed in the future.
Instead, the <a href="book.mysqli.html" class="link">MySQLi</a> or <a href="ref.pdo-mysql.html" class="link">PDO_MySQL</a> extension should be used.
See also <a href="mysqlinfo.api.choosing.html" class="link">MySQL: choosing an API</a> guide and
<a href="faq.databases.html#faq.databases.mysql.deprecated" class="link">related FAQ</a> for more information.
Alternatives to this function include:</p>
<ul class="simplelist">
<li class="member"> <span class="function"><a href="mysqli-result.fetch-field.html" class="function">mysqli_fetch_field()</a></span></li>
<li class="member"> <span class="methodname"><a href="pdostatement.getcolumnmeta.html" class="methodname">PDOStatement::getColumnMeta()</a></span></li>
</ul>
</div>
</div>
<div class="refsect1 description" id="refsect1-function.mysql-fetch-field-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">object</span> <span class="methodname"><strong>mysql_fetch_field</strong></span>
( <span class="methodparam"><span class="type">resource</span> <code class="parameter">$result</code></span>
[, <span class="methodparam"><span class="type">int</span> <code class="parameter">$field_offset</code><span class="initializer"> = 0</span></span>
] )</div>
<p class="para rdfs-comment">
Returns an object containing field information. This function can be used
to obtain information about fields in the provided query result.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.mysql-fetch-field-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">
result</code></em></span><dd>
<p class="para">The result <span class="type"><a href="language.types.resource.html" class="type resource">resource</a></span> that
is being evaluated. This result comes from a call to
<span class="function"><a href="function.mysql-query.html" class="function">mysql_query()</a></span>.</p></dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">field_offset</code></em></span>
<dd>
<p class="para">
The numerical field offset. If the field offset is not specified, the
next field that was not yet retrieved by this function is retrieved.
The <em><code class="parameter">field_offset</code></em> starts at <em>0</em>.
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.mysql-fetch-field-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns an <span class="type"><a href="language.types.object.html" class="type object">object</a></span> containing field information. The properties
of the object are:
</p>
<p class="para">
<ul class="itemizedlist">
<li class="listitem">
<span class="simpara">
name - column name
</span>
</li>
<li class="listitem">
<span class="simpara">
table - name of the table the column belongs to, which is the alias name if one is defined
</span>
</li>
<li class="listitem">
<span class="simpara">
max_length - maximum length of the column
</span>
</li>
<li class="listitem">
<span class="simpara">
not_null - 1 if the column cannot be <strong><code>NULL</code></strong>
</span>
</li>
<li class="listitem">
<span class="simpara">
primary_key - 1 if the column is a primary key
</span>
</li>
<li class="listitem">
<span class="simpara">
unique_key - 1 if the column is a unique key
</span>
</li>
<li class="listitem">
<span class="simpara">
multiple_key - 1 if the column is a non-unique key
</span>
</li>
<li class="listitem">
<span class="simpara">
numeric - 1 if the column is numeric
</span>
</li>
<li class="listitem">
<span class="simpara">
blob - 1 if the column is a BLOB
</span>
</li>
<li class="listitem">
<span class="simpara">
type - the type of the column
</span>
</li>
<li class="listitem">
<span class="simpara">
unsigned - 1 if the column is unsigned
</span>
</li>
<li class="listitem">
<span class="simpara">
zerofill - 1 if the column is zero-filled
</span>
</li>
</ul>
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.mysql-fetch-field-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-1584">
<p><strong>Example #1 <span class="function"><strong>mysql_fetch_field()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />$conn </span><span style="color: #007700">= </span><span style="color: #0000BB">mysql_connect</span><span style="color: #007700">(</span><span style="color: #DD0000">'localhost'</span><span style="color: #007700">, </span><span style="color: #DD0000">'mysql_user'</span><span style="color: #007700">, </span><span style="color: #DD0000">'mysql_password'</span><span style="color: #007700">);<br />if (!</span><span style="color: #0000BB">$conn</span><span style="color: #007700">) {<br /> die(</span><span style="color: #DD0000">'Could not connect: ' </span><span style="color: #007700">. </span><span style="color: #0000BB">mysql_error</span><span style="color: #007700">());<br />}<br /></span><span style="color: #0000BB">mysql_select_db</span><span style="color: #007700">(</span><span style="color: #DD0000">'database'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$result </span><span style="color: #007700">= </span><span style="color: #0000BB">mysql_query</span><span style="color: #007700">(</span><span style="color: #DD0000">'select * from table'</span><span style="color: #007700">);<br />if (!</span><span style="color: #0000BB">$result</span><span style="color: #007700">) {<br /> die(</span><span style="color: #DD0000">'Query failed: ' </span><span style="color: #007700">. </span><span style="color: #0000BB">mysql_error</span><span style="color: #007700">());<br />}<br /></span><span style="color: #FF8000">/* get column metadata */<br /></span><span style="color: #0000BB">$i </span><span style="color: #007700">= </span><span style="color: #0000BB">0</span><span style="color: #007700">;<br />while (</span><span style="color: #0000BB">$i </span><span style="color: #007700">< </span><span style="color: #0000BB">mysql_num_fields</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">)) {<br /> echo </span><span style="color: #DD0000">"Information for column </span><span style="color: #0000BB">$i</span><span style="color: #DD0000">:<br />\n"</span><span style="color: #007700">;<br /> </span><span style="color: #0000BB">$meta </span><span style="color: #007700">= </span><span style="color: #0000BB">mysql_fetch_field</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">, </span><span style="color: #0000BB">$i</span><span style="color: #007700">);<br /> if (!</span><span style="color: #0000BB">$meta</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">"No information available<br />\n"</span><span style="color: #007700">;<br /> }<br /> echo </span><span style="color: #DD0000">"<pre><br />blob: </span><span style="color: #0000BB">$meta</span><span style="color: #007700">-></span><span style="color: #0000BB">blob</span><span style="color: #DD0000"><br />max_length: </span><span style="color: #0000BB">$meta</span><span style="color: #007700">-></span><span style="color: #0000BB">max_length</span><span style="color: #DD0000"><br />multiple_key: </span><span style="color: #0000BB">$meta</span><span style="color: #007700">-></span><span style="color: #0000BB">multiple_key</span><span style="color: #DD0000"><br />name: </span><span style="color: #0000BB">$meta</span><span style="color: #007700">-></span><span style="color: #0000BB">name</span><span style="color: #DD0000"><br />not_null: </span><span style="color: #0000BB">$meta</span><span style="color: #007700">-></span><span style="color: #0000BB">not_null</span><span style="color: #DD0000"><br />numeric: </span><span style="color: #0000BB">$meta</span><span style="color: #007700">-></span><span style="color: #0000BB">numeric</span><span style="color: #DD0000"><br />primary_key: </span><span style="color: #0000BB">$meta</span><span style="color: #007700">-></span><span style="color: #0000BB">primary_key</span><span style="color: #DD0000"><br />table: </span><span style="color: #0000BB">$meta</span><span style="color: #007700">-></span><span style="color: #0000BB">table</span><span style="color: #DD0000"><br />type: </span><span style="color: #0000BB">$meta</span><span style="color: #007700">-></span><span style="color: #0000BB">type</span><span style="color: #DD0000"><br />unique_key: </span><span style="color: #0000BB">$meta</span><span style="color: #007700">-></span><span style="color: #0000BB">unique_key</span><span style="color: #DD0000"><br />unsigned: </span><span style="color: #0000BB">$meta</span><span style="color: #007700">-></span><span style="color: #0000BB">unsigned</span><span style="color: #DD0000"><br />zerofill: </span><span style="color: #0000BB">$meta</span><span style="color: #007700">-></span><span style="color: #0000BB">zerofill</span><span style="color: #DD0000"><br /></pre>"</span><span style="color: #007700">;<br /> </span><span style="color: #0000BB">$i</span><span style="color: #007700">++;<br />}<br /></span><span style="color: #0000BB">mysql_free_result</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</p>
</div>
<div class="refsect1 notes" id="refsect1-function.mysql-fetch-field-notes">
<h3 class="title">Notes</h3>
<blockquote class="note"><p><strong class="note">Note</strong>: <span class="simpara">Field names returned by this function
are <em class="emphasis">case-sensitive</em>.</span></p></blockquote>
<blockquote class="note"><p><strong class="note">Note</strong>:
<p class="para">
If field or tablenames are aliased in the SQL query the aliased name will
be returned. The original name can be retrieved for instance by using
<span class="methodname"><a href="mysqli-result.fetch-field.html" class="methodname">mysqli_result::fetch_field()</a></span>.
</p>
</p></blockquote>
</div>
<div class="refsect1 seealso" id="refsect1-function.mysql-fetch-field-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"> <span class="function"><a href="function.mysql-field-seek.html" class="function" rel="rdfs-seeAlso">mysql_field_seek()</a> - Set result pointer to a specified field offset</span></li>
</ul>
</p>
</div>
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