friendica/static/dbview.config.php

<?php
/**
 * @copyright Copyright (C) 2020, Friendica
 *
 * @license GNU AGPL version 3 or any later version
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 * Main view structure configuration file.
 *
 * Here are described all the view Friendica needs to work.
 *
 * Syntax (braces indicate optionale values):
 * "<view name>" => [
 *	"fields" => [
 *		"<field name>" => ["table", "field"],
 *		"<field name>" => "SQL expression",
 *		...
 *	],
 *	"query" => "FROM `table` INNER JOIN `other-table` ..."
 *	],
 * ],
 *
 * If you need to make any change, make sure to increment the DB_UPDATE_VERSION constant value in dbstructure.config.php.
 *
 */

return [
	"tag-view" => [
		"fields" => [
			"uri-id" => ["post-tag", "uri-id"],
			"uri" => ["item-uri", "uri"],
			"guid" => ["item-uri", "guid"],
			"type" => ["post-tag", "type"],
			"tid" => ["post-tag", "tid"],
			"cid" => ["post-tag", "cid"],
			"name" => "CASE `cid` WHEN 0 THEN `tag`.`name` ELSE `contact`.`name` END",
			"url" => "CASE `cid` WHEN 0 THEN `tag`.`url` ELSE `contact`.`url` END",
		],
		"query" => "FROM `post-tag`
			INNER JOIN `item-uri` ON `item-uri`.id = `post-tag`.`uri-id`
			LEFT JOIN `tag` ON `post-tag`.`tid` = `tag`.`id`
			LEFT JOIN `contact` ON `post-tag`.`cid` = `contact`.`id`"
	]
];