We now can define views

database.sql

@@ -1,6 +1,6 @@
 -- ------------------------------------------
 -- Friendica 2020.06-dev (Red Hot Poker)
--- DB_UPDATE_VERSION 1338
+-- DB_UPDATE_VERSION 1340
 -- ------------------------------------------
 
 
@@ -1175,6 +1175,31 @@ CREATE TABLE IF NOT EXISTS `term` (
 	 INDEX `guid` (`guid`(64))
 ) DEFAULT COLLATE utf8mb4_general_ci COMMENT='item taxonomy (categories, tags, etc.) table';
 
+--
+-- TABLE tag
+--
+CREATE TABLE IF NOT EXISTS `tag` (
+	`id` int unsigned NOT NULL auto_increment COMMENT '',
+	`name` varchar(96) NOT NULL DEFAULT '' COMMENT '',
+	`url` varbinary(255) NOT NULL DEFAULT '' COMMENT '',
+	 PRIMARY KEY(`id`),
+	 UNIQUE INDEX `type_name_url` (`name`,`url`),
+	 INDEX `url` (`url`)
+) DEFAULT COLLATE utf8mb4_general_ci COMMENT='tags and mentions';
+
+--
+-- TABLE post-tag
+--
+CREATE TABLE IF NOT EXISTS `post-tag` (
+	`uri-id` int unsigned NOT NULL COMMENT 'Id of the item-uri table entry that contains the item uri',
+	`type` tinyint unsigned NOT NULL DEFAULT 0 COMMENT '',
+	`tid` int unsigned NOT NULL DEFAULT 0 COMMENT '',
+	`cid` int unsigned NOT NULL DEFAULT 0 COMMENT 'Contact id of the mentioned public contact',
+	 PRIMARY KEY(`uri-id`,`type`,`tid`,`cid`),
+	 INDEX `uri-id` (`tid`),
+	 INDEX `cid` (`tid`)
+) DEFAULT COLLATE utf8mb4_general_ci COMMENT='post relation to tags';
+
 --
 -- TABLE thread
 --
@@ -1361,4 +1386,22 @@ CREATE TABLE IF NOT EXISTS `storage` (
 	 PRIMARY KEY(`id`)
 ) DEFAULT COLLATE utf8mb4_general_ci COMMENT='Data stored by Database storage backend';
 
+--
+-- VIEW tag-view
+--
+DROP VIEW IF EXISTS `tag-view`;
+CREATE VIEW `tag-view` AS SELECT 
+	`post-tag`.`uri-id` AS `uri-id`,
+	`item-uri`.`uri` AS `uri`,
+	`item-uri`.`guid` AS `guid`,
+	`post-tag`.`type` AS `type`,
+	`post-tag`.`tid` AS `tid`,
+	`post-tag`.`cid` AS `cid`,
+	CASE `cid` WHEN 0 THEN `tag`.`name` ELSE `contact`.`name` END AS `name`,
+	CASE `cid` WHEN 0 THEN `tag`.`url` ELSE `contact`.`url` END AS `url`
+	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`;
+
 

src/Database/DBStructure.php

@@ -112,6 +112,8 @@ class DBStructure
 
 			echo "\n";
 		}
+
+		DBView::printStructure($basePath);
 	}
 
 	/**
@@ -594,6 +596,8 @@ class DBStructure
 			}
 		}
 
+		DBView::create($verbose, $action);
+
 		if ($action && !$install) {
 			DI::config()->set('system', 'maintenance', 0);
 			DI::config()->set('system', 'maintenance_reason', '');

src/Database/DBView.php

@@ -0,0 +1,138 @@
+<?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/>.
+ *
+ */
+
+namespace Friendica\Database;
+
+use Exception;
+use Friendica\Core\Hook;
+use Friendica\Core\Logger;
+use Friendica\DI;
+use Friendica\Util\DateTimeFormat;
+use phpDocumentor\Reflection\Types\Boolean;
+
+require_once __DIR__ . '/../../include/dba.php';
+
+class DBView
+{
+	/**
+	 * view definition loaded from config/dbview.config.php
+	 *
+	 * @var array
+	 */
+	private static $definition = [];
+
+	/**
+	 * Loads the database structure definition from the config/dbview.config.php file.
+	 * On first pass, defines DB_UPDATE_VERSION constant.
+	 *
+	 * @see static/dbview.config.php
+	 * @param boolean $with_addons_structure Whether to tack on addons additional tables
+	 * @param string  $basePath              The base path of this application
+	 * @return array
+	 * @throws Exception
+	 */
+	public static function definition($basePath = '', $with_addons_structure = true)
+	{
+		if (!self::$definition) {
+			if (empty($basePath)) {
+				$basePath = DI::app()->getBasePath();
+			}
+
+			$filename = $basePath . '/static/dbview.config.php';
+
+			if (!is_readable($filename)) {
+				throw new Exception('Missing database view config file static/dbview.config.php');
+			}
+
+			$definition = require $filename;
+
+			if (!$definition) {
+				throw new Exception('Corrupted database view config file static/dbview.config.php');
+			}
+
+			self::$definition = $definition;
+		} else {
+			$definition = self::$definition;
+		}
+
+		if ($with_addons_structure) {
+			Hook::callAll('dbview_definition', $definition);
+		}
+
+		return $definition;
+	}
+
+	public static function create(bool $verbose, bool $action)
+	{
+		$definition = self::definition();
+
+		foreach ($definition as $name => $structure) {
+			self::createview($name, $structure, $verbose, $action);
+		}
+	}
+
+	public static function printStructure($basePath)
+	{
+		$database = self::definition($basePath, false);
+
+		foreach ($database AS $name => $structure) {
+			echo "--\n";
+			echo "-- VIEW $name\n";
+			echo "--\n";
+			self::createView($name, $structure, true, false);
+
+			echo "\n";
+		}
+	}
+
+	private static function createview($name, $structure, $verbose, $action)
+	{
+		$r = true;
+
+		$sql_rows = [];
+		foreach ($structure["fields"] AS $fieldname => $origin) {
+			$sql_rows[] = $origin . " AS `" . DBA::escape($fieldname) . "`";
+		}
+
+		$sql = sprintf("DROP VIEW IF EXISTS `%s`", DBA::escape($name));
+
+		if ($verbose) {
+			echo $sql . ";\n";
+		}
+
+		if ($action) {
+			DBA::e($sql);
+		}
+
+		$sql = sprintf("CREATE VIEW `%s` AS SELECT \n\t", DBA::escape($name)) .
+			implode(",\n\t", $sql_rows) . "\n\t" . $structure['query'];
+	
+		if ($verbose) {
+			echo $sql . ";\n";
+		}
+
+		if ($action) {
+			$r = DBA::e($sql);
+		}
+
+		return $r;
+	}
+}

static/dbstructure.config.php

@@ -51,7 +51,7 @@
 use Friendica\Database\DBA;
 
 if (!defined('DB_UPDATE_VERSION')) {
-	define('DB_UPDATE_VERSION', 1339);
+	define('DB_UPDATE_VERSION', 1340);
 }
 
 return [

static/dbview.config.php

@@ -0,0 +1,56 @@
+<?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>" => "`other-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`"
+	]
+];
+