>>> [!note] Migrated issue <!-- Drupal.org comment --> <!-- Migrated from issue #1917088. --> Reported by: [Julian Maurice](https://www.drupal.org/user/2221570) >>> <p>This module provides a data alteration callback for Search API very similar to 'Aggregate Fields', but instead of reducing fields values into a single value, it keeps fields values "as is" so they are indexed into multi-valued indexes.</p> <p><b>Drupal version:</b> 7<br> <b>Required modules:</b> Search API<br> <b>Sandbox project:</b> <a href="http://drupal.org/sandbox/jajm/1870400">http://drupal.org/sandbox/jajm/1870400</a><br> <b>Git repository:</b> <code>git clone --recursive --branch 7.x-1.x http://git.drupal.org/sandbox/jajm/1870400.git search_api_multi_aggregate</code></p> <h2>Why you need it?</h2> <p>This module is useful when you want to aggregate fields and index the new field as string (for faceting for example).</p> <h3>Example</h3> <p>You have 2 fields:</p> <ul> <li><strong>Primary authors</strong> which contains the following values <ul> <li><code>"Primary 1"</code></li> <li><code>"Primary 2"</code></li> </ul> </li> <li><strong>Secondary authors</strong> which contains the following values <ul> <li><code>"Secondary 1"</code></li> <li><code>"Secondary 2"</code></li> </ul> </li> </ul> <p>and you want them both to be used in one single Facet block.<br> You have to create a new field that will contains values of both these fields.<br> You can use the 'Aggregate Fields' that comes with Search API module for that. But there is a small inconvenient:</p> <ul> <li>If you index the new field as "Fulltext", your facets will looks like <ul> <li><code>"Primary"</code></li> <li><code>"Secondary"</code></li> <li><code>"1"</code></li> <li><code>"2"</code></li> </ul> </li> <li>If you index the new field as "String", you will get only one facet: <ul> <li><code>"Primary 1 Primary 2 Secondary 1 Secondary 2"</code></li> </ul> </li> </ul> <p>Using Search API Multi Aggregate will allow you to have the facets you want:</p> <ul> <li><code>"Primary 1"</code></li> <li><code>"Primary 2"</code></li> <li><code>"Secondary 1"</code></li> <li><code>"Secondary 2"</code></li> </ul> <h2>How to use it?</h2> <ol> <li>Install and enable the module</li> <li>Go to your Search API Index configuration, under Workflow tab</li> <li>You should see a new type of data alteration: "Aggregated fields (multi-valued)". Enable it</li> <li>Under "callback settings", click on "Add new field" and configure it (fill its name and choose the fields to aggregate)</li> <li>You should now see a new field in the fields list. Check it and choose "String" type</li> <li>Re-index</li> </ol>