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<div class="section" id="relations">
<span id="id1"></span><h1>Relations<a class="headerlink" href="#relations" title="Permalink to this headline">¶</a></h1>
<p>phpMyAdmin allows relationships (similar to foreign keys) using MySQL-native
(InnoDB) methods when available and falling back on special phpMyAdmin-only
features when needed. There are two ways of editing these relations, with the
<em>relation view</em> and the drag-and-drop <em>designer</em> – both of which are explained
on this page.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>You need to have configured the <a class="reference internal" href="setup.html#linked-tables"><span class="std std-ref">phpMyAdmin configuration storage</span></a> for using phpMyAdmin
only relations.</p>
</div>
<div class="section" id="technical-info">
<h2>Technical info<a class="headerlink" href="#technical-info" title="Permalink to this headline">¶</a></h2>
<p>Currently the only MySQL table type that natively supports relationships is
InnoDB. When using an InnoDB table, phpMyAdmin will create real InnoDB
relations which will be enforced by MySQL no matter which application accesses
the database. In the case of any other table type, phpMyAdmin enforces the
relations internally and those relations are not applied to any other
application.</p>
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<div class="section" id="relation-view">
<h2>Relation view<a class="headerlink" href="#relation-view" title="Permalink to this headline">¶</a></h2>
<p>In order to get it working, you first have to properly create the
[[pmadb|pmadb]]. Once that is setup, select a table’s “Structure” page. Below
the table definition, a link called “Relation view” is shown. If you click that
link, a page will be shown that offers you to create a link to another table
for any (most) fields. Only PRIMARY KEYS are shown there, so if the field you
are referring to is not shown, you most likely are doing something wrong. The
drop-down at the bottom is the field which will be used as the name for a
record.</p>
<div class="section" id="relation-view-example">
<h3>Relation view example<a class="headerlink" href="#relation-view-example" title="Permalink to this headline">¶</a></h3>
<img alt="_images/pma-relations-relation-view-link.png" src="_images/pma-relations-relation-view-link.png" />
<img alt="_images/pma-relations-relation-link.png" src="_images/pma-relations-relation-link.png" />
<p>Let’s say you have categories and links and one category can contain several links. Your table structure would be something like this:</p>
<ul class="simple">
<li><p><cite>category.category_id</cite> (must be unique)</p></li>
<li><p><cite>category.name</cite></p></li>
<li><p><cite>link.link_id</cite></p></li>
<li><p><cite>link.category_id</cite></p></li>
<li><p><cite>link.uri</cite>.</p></li>
</ul>
<p>Open the relation view (below the table structure) page for the <cite>link</cite> table and for <cite>category_id</cite> field, you select <cite>category.category_id</cite> as master record.</p>
<p>If you now browse the link table, the <cite>category_id</cite> field will be a clickable hyperlink to the proper category record. But all you see is just the <cite>category_id</cite>, not the name of the category.</p>
<img alt="_images/pma-relations-relation-name.png" src="_images/pma-relations-relation-name.png" />
<p>To fix this, open the relation view of the <cite>category</cite> table and in the drop down at the bottom, select “name”. If you now browse the link table again and hover the mouse over the <cite>category_id</cite> hyperlink, the value from the related category will be shown as tooltip.</p>
<img alt="_images/pma-relations-links.png" src="_images/pma-relations-links.png" />
</div>
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<div class="section" id="designer">
<h2>Designer<a class="headerlink" href="#designer" title="Permalink to this headline">¶</a></h2>
<p>The Designer feature is a graphical way of creating, editing, and displaying
phpMyAdmin relations. These relations are compatible with those created in
phpMyAdmin’s relation view.</p>
<p>To use this feature, you need a properly configured <a class="reference internal" href="setup.html#linked-tables"><span class="std std-ref">phpMyAdmin configuration storage</span></a> and
must have the <span class="target" id="index-0"></span><a class="reference internal" href="config.html#cfg_Servers_table_coords"><code class="xref config config-option docutils literal notranslate"><span class="pre">$cfg['Servers'][$i]['table_coords']</span></code></a> configured.</p>
<p>To use the designer, select a database’s structure page, then look for the
<span class="guilabel">Designer</span> tab.</p>
<p>To export the view into PDF, you have to create PDF pages first. The Designer
creates the layout, how the tables shall be displayed. To finally export the
view, you have to create this with a PDF page and select your layout, which you
have created with the designer.</p>
<div class="admonition seealso">
<p class="admonition-title">See also</p>
<p><a class="reference internal" href="faq.html#faqpdf"><span class="std std-ref">6.8 How can I produce a PDF schema of my database?</span></a></p>
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<h3><a href="index.html">Table of Contents</a></h3>
<ul>
<li><a class="reference internal" href="#">Relations</a><ul>
<li><a class="reference internal" href="#technical-info">Technical info</a></li>
<li><a class="reference internal" href="#relation-view">Relation view</a><ul>
<li><a class="reference internal" href="#relation-view-example">Relation view example</a></li>
</ul>
</li>
<li><a class="reference internal" href="#designer">Designer</a></li>
</ul>
</li>
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