Breaking: #17406 - Field "url" in table "pages" has been removed 

Description 

The former page type "External link" has been renamed to "Link" and now fully supports all typolink capabilities. It now uses the field link.

Since the field url was only used by this former page type, it has been removed.

Impact 

Custom code that expects the field url to exist in the table pages will fail as the field is not found anymore.

Affected installations 

• TYPO3 projects that used the former page type External URL to link to resources other than true external URLs, for example sections such as #abc.
• TYPO3 projects with custom code that expects the field url to exist in the table pages.

Migration 

The upgrade wizard "Migrate links of pages of type link" automatically migrates pages of the former type External URL to the new page type Link.

It migrates all links that resolve to external URLs. If your project used the External URL field for other purposes — for example, to link sections such as #abc — you must migrate those links manually.

If your project contains custom code that expects the field url to exist in the table pages, you can reintroduce this field via a TCA override, for example:

<?php

defined('TYPO3') || die('Access restricted.');

$GLOBALS['TCA']['pages']['columns']['url'] = [
    'label' => 'External URL',
    'config' => [
        'type' => 'input',
        'size' => 50,
        'max' => 255,
        'required' => true,
        'eval' => 'trim',
        'softref' => 'url',
        'behaviour' => [
            'allowLanguageSynchronization' => true,
        ],
    ],
];

// Adding column to a existing or new palette and configure showitem,
// for a specific doktype the field is still required, for example:
$GLOBALS['TCA']['pages']['palettes]['custom_url'] = [
    'showitem' => 'url',
];
$GLOBALS['TCA']['pages']['types'][$customDokTypeValue] = [
    'showitem' => [
        --div--;core.form.tabs:general,
            doktype,
            --palette--;;title,
            --palette--;;custom_url,
    ],
];

Adding it back at least ensures that the database field is not renamed and dropped by the Database Analyzer. In case TCA is not required while keeping the database field it could be added to a extension ext_tables.sql file.