function.mysql-fetch-field.html
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html> <head> <title>Get column information from a result and return as an object</title> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> </head> <body><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.mysql-fetch-assoc.html">mysql_fetch_assoc</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.mysql-fetch-lengths.html">mysql_fetch_lengths</a></div> <div class="up"><a href="ref.mysql.html">MySQL Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div><hr /><div id="function.mysql-fetch-field" class="refentry"> <div class="refnamediv"> <h1 class="refname">mysql_fetch_field</h1> <p class="verinfo">(PHP 4, PHP 5, PECL mysql:1.0)</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 class="refsect1 description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="type">object</span> <span class="methodname"><b><b>mysql_fetch_field</b></b></span> ( <span class="methodparam"><span class="type">resource</span> <tt class="parameter">$result</tt></span> [, <span class="methodparam"><span class="type">int</span> <tt class="parameter">$field_offset</tt></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"> <h3 class="title">Parameters</h3> <p class="para"> <dl> <dt><span class="term"><i><tt class="parameter">result</tt></i></span><dd><p class="para">The result <a href="language.types.resource.html" class="type resource">resource</a> thatis being evaluated. This result comes from a call to <a href="function.mysql-query.html" class="function">mysql_query()</a>.</p></dd></dt> <dt> <span class="term"><i><tt class="parameter">field_offset</tt></i></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 <i><tt class="parameter">field_offset</tt></i> starts at <i>0</i>. </p> </dd> </dt> </dl> </p> </div> <div class="refsect1 returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> Returns an <a href="language.types.object.html" class="type object">object</a> 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 </span> </li> <li class="listitem"> <span class="simpara"> def - default value of the column </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 <b><tt>NULL</tt></b> </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"> <h3 class="title">Examples</h3> <p class="para"> <div class="example"> <p><b>Example #1 <b>mysql_fetch_field()</b> example</b></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 $i:<br />\n"</span><span style="color: #007700">;<br /> </span><span style="color: #0000BB">$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: $meta->blob<br />max_length: $meta->max_length<br />multiple_key: $meta->multiple_key<br />name: $meta->name<br />not_null: $meta->not_null<br />numeric: $meta->numeric<br />primary_key: $meta->primary_key<br />table: $meta->table<br />type: $meta->type<br />default: $meta->def<br />unique_key: $meta->unique_key<br />unsigned: $meta->unsigned<br />zerofill: $meta->zerofill<br /></pre>"</span><span style="color: #007700">;<br /> </span><span style="color: #0000BB">$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"> <h3 class="title">Notes</h3> <blockquote><p><b class="note">Note</b>: <span class="simpara">Field names returned by this functionare <em class="emphasis">case-sensitive</em>.</span></p></blockquote> </div> <div class="refsect1 seealso"> <h3 class="title">See Also</h3> <p class="para"> <ul class="simplelist"> <li class="member"><a href="function.mysql-field-seek.html" class="function" rel="rdfs-seeAlso">mysql_field_seek()</a></li> </ul> </p> </div></div><hr /><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.mysql-fetch-assoc.html">mysql_fetch_assoc</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.mysql-fetch-lengths.html">mysql_fetch_lengths</a></div> <div class="up"><a href="ref.mysql.html">MySQL 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