Eduardo Marcolino

This ACF plugin makes it possible to store ACF data in structured database tables instead of WordPress core meta tables.
It uses ACF’s <code>acf/update_field_group</code> hook to create/update the database and then uses <code>acf/save_post</code> hook to store the data.
It was heavily inspired by Austin Ginder’s post <a href="https://anchor.host/acf-custom-fields-stored-in-custom-table/" rel="nofollow ugc">https://anchor.host/acf-custom-fields-stored-in-custom-table/</a>.
You can contribute to this plugin by submit PR/Issue in <a href="https://github.com/eduardo-marcolino/acf-fields-in-custom-table" rel="nofollow ugc">https://github.com/eduardo-marcolino/acf-fields-in-custom-table</a>.
<h4>Supported Fields</h4>
<ul>
<li>Text</li>
<li>Text Area</li>
<li>Number</li>
<li>Range</li>
<li>Email</li>
<li>URL</li>
<li>Password</li>
<li>Image</li>
<li>File</li>
<li>Wysiwyg Editor</li>
<li>oEmbed</li>
<li>Select</li>
<li>Checkbox</li>
<li>Radio Button</li>
<li>Button Group</li>
<li>True / False</li>
<li>Date Picker</li>
<li>Date Time Picker</li>
<li>Time Picker</li>
<li>Color Picker</li>
<li>Link</li>
<li>Post Object</li>
<li>Page Link</li>
<li>Relationship</li>
<li>Taxonomy</li>
<li>User</li>
</ul>
<h4>Relational Fields</h4>
This plugin supports the following relational field types: Post Object, Page Link, Relationship, Taxonomy and User.
It can store both single and multiple values based on the <code>multiple</code> option.
<ul>
<li>If it’s a single value field, then the column type will be <code>bigint(20) unsigned</code></li>
<li>If it’s a multiple value field, then the column type will be longtext and the date will be stored in json format.</li>
</ul>
You can query relational fields with multiple values using using MySQL’s function <a href="https://dev.mysql.com/doc/refman/5.7/en/json-search-functions.html#function_json-contains" rel="nofollow ugc">JSON_CONTAINS</a>. 
Here is an example:
Table:
<pre><code>+---------+-------------------+--------+
| post_id | title | stores |
+---------+-------------------+--------+
| 1 | Lord of the Flies | [1,2] |
| 2 | The Island | [2] |
| 3 | 1984 | [3] |
+---------+-------------------+--------+
</code></pre>
Query:
<pre><code>SELECT * FROM wp_acf_books WHERE JSON_CONTAINS(stores, 2, '$')
</code></pre>
The query above will return “Lord of the Flies” and “The Island”.
<h4>ACF Compatibility</h4>
This plugin was tested with ACF 5 FREE Version .

ACF: Fields in Custom Table

Stores ACF custom fields in a custom table instead of WordPress core meta tables.

pixelgrade

George Olaru

Andrei Lupu

With <a href="https://github.com/pixelgrade/pixfields" rel="nofollow ugc">PixFields</a> you can have a custom fields visual manager.
Note: this plugin does not add any style to the output of custom fields. Its just adding metadata and offers a way to overwrite the html from the theme. 
The theme should style the output of the metadata.

PixFields

PixFields offers you a nice interface to add custom metadata into your favorite post type.

ACF: Fields in Custom Table vs PixFields