Edit Account – read and write to MySQL

User meta information, like that on the profile page, is stored in the usermeta table in the database. You can add extra fields by hooking into the show_user_profile and edit_user_profile action hooks. Then you can save the information by hooking into the personal_options_update and edit_user_profile_update action hooks with a function that updates the new field in the user meta table, update_user_meta().

First create the fields to be rendered on the profile page

//display extra profile fields
add_action( 'show_user_profile', 'extra_profile_fields' );
add_action( 'edit_user_profile', 'extra_profile_fields' );

function extra_profile_fields( $user )
{
    ?>
        <h3>Extra Profile Fields</h3>

        <table class="form-table">
            <tr>
                <th><label for="UID-Nummer"><?php _e( 'UID-Nummer', 'woocommerce' ); ?></label></th>
                <td><input type="text" name="uid-nummer" value="<?php echo esc_attr( get_the_author_meta( 'uid-nummer', $user->ID ) ); ?>" class="regular-text" /></td>
            </tr>
        </table>
    <?php
}

Note the name attribute. It’s a good idea to use this same name when saving the field. You can see that we are pulling that field into the value already using get_the_author_meta( 'uid-nummer', $user->ID ).

Save the fields

//save extra profile fields
add_action( 'personal_options_update', 'save_extra_profile_fields' );
add_action( 'edit_user_profile_update', 'save_extra_profile_fields' );

function save_extra_profile_fields( $user_id )
{
    update_user_meta( $user_id,'uid-nummer', sanitize_text_field( $_POST['uid-nummer'] ) );
}

Using the fields

To display the field ui-nummer you can use either:

//return the author meta
get_the_author_meta( 'ui-nummer', $user->ID );

or

//echo the author meta
the_author_meta( 'ui-nummer', $user->ID );