From dc62342b6dd914cb1448b3ed1bdcd1e405161f20 Mon Sep 17 00:00:00 2001
From: Matthias Schmidt <gravatronics@live.com>
Date: Tue, 6 Aug 2019 19:53:38 +0200
Subject: [PATCH] Add DatabaseEditor::(getForeignKeys|getIndexInformation)()

---
 .../database/editor/DatabaseEditor.class.php  | 24 ++++-
 .../editor/MySQLDatabaseEditor.class.php      | 88 +++++++++++++++++++
 2 files changed, 110 insertions(+), 2 deletions(-)

diff --git a/wcfsetup/install/files/lib/system/database/editor/DatabaseEditor.class.php b/wcfsetup/install/files/lib/system/database/editor/DatabaseEditor.class.php
index 3592bd0e97..15eaf875c7 100644
--- a/wcfsetup/install/files/lib/system/database/editor/DatabaseEditor.class.php
+++ b/wcfsetup/install/files/lib/system/database/editor/DatabaseEditor.class.php
@@ -1,6 +1,7 @@
 <?php
 namespace wcf\system\database\editor;
 use wcf\system\database\Database;
+use wcf\system\exception\NotImplementedException;
 
 /**
  * Abstract implementation of a database editor.
@@ -42,13 +43,32 @@ abstract class DatabaseEditor {
 	abstract public function getColumns($tableName);
 	
 	/**
-	 * Returns the indices of a table.
+	 * Returns information on the foreign keys of a table.
+	 * 
+	 * @return	array
+	 */
+	public function getForeignKeys($tableName) {
+		throw new NotImplementedException();
+	}
+	
+	/**
+	 * Returns the names of the indices of a table.
 	 * 
 	 * @param	string		$tableName
-	 * @return	array		$indices
+	 * @return	string[]	$indices
 	 */
 	abstract public function getIndices($tableName);
 	
+	/**
+	 * Returns information on the indices of a table.
+	 * 
+	 * @param	string		$tableName
+	 * @return	array
+	 */
+	public function getIndexInformation($tableName) {
+		throw new NotImplementedException();
+	}
+	
 	/**
 	 * Creates a new database table.
 	 * 
diff --git a/wcfsetup/install/files/lib/system/database/editor/MySQLDatabaseEditor.class.php b/wcfsetup/install/files/lib/system/database/editor/MySQLDatabaseEditor.class.php
index 80b2cf98bc..0f22908e5e 100644
--- a/wcfsetup/install/files/lib/system/database/editor/MySQLDatabaseEditor.class.php
+++ b/wcfsetup/install/files/lib/system/database/editor/MySQLDatabaseEditor.class.php
@@ -52,6 +52,94 @@ class MySQLDatabaseEditor extends DatabaseEditor {
 		return $columns;
 	}
 	
+	/**
+	 * @inheritDoc
+	 */
+	public function getForeignKeys($tableName) {
+		$sql = "SELECT		key_column_usage.CONSTRAINT_NAME,
+					key_column_usage.COLUMN_NAME,
+					key_column_usage.REFERENCED_TABLE_NAME,
+					key_column_usage.REFERENCED_COLUMN_NAME,
+					referential_constraints.DELETE_RULE,
+					referential_constraints.UPDATE_RULE
+			FROM		INFORMATION_SCHEMA.KEY_COLUMN_USAGE key_column_usage
+			INNER JOIN	INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS referential_constraints
+			ON 		(referential_constraints.CONSTRAINT_NAME = key_column_usage.CONSTRAINT_NAME
+					AND referential_constraints.CONSTRAINT_SCHEMA = key_column_usage.TABLE_SCHEMA
+					AND referential_constraints.TABLE_NAME = key_column_usage.TABLE_NAME)
+			WHERE		key_column_usage.TABLE_SCHEMA = ?
+					AND key_column_usage.TABLE_NAME = ?";
+		$statement = $this->dbObj->prepareStatement($sql);
+		$statement->execute([
+			$this->dbObj->getDatabaseName(),
+			$tableName
+		]);
+		$keyInformation = $statement->fetchAll(\PDO::FETCH_ASSOC);
+		
+		$validActions = ['CASCADE', 'SET NULL', 'NO ACTION'];
+		
+		$foreignKeys = [];
+		foreach ($keyInformation as $information) {
+			if (!isset($foreignKeys[$information['CONSTRAINT_NAME']])) {
+				$foreignKeys[$information['CONSTRAINT_NAME']] = [
+					'columns' => [$information['COLUMN_NAME']],
+					'referencedColumns' => [$information['REFERENCED_COLUMN_NAME']],
+					'referencedTable' => $information['REFERENCED_TABLE_NAME'],
+					'ON DELETE' => in_array($information['DELETE_RULE'], $validActions) ? $information['DELETE_RULE'] : null,
+					'ON UPDATE' => in_array($information['UPDATE_RULE'], $validActions) ? $information['UPDATE_RULE'] : null
+				];
+			}
+			else {
+				$foreignKeys[$information['CONSTRAINT_NAME']]['columns'][] = $information['COLUMN_NAME'];
+				$foreignKeys[$information['CONSTRAINT_NAME']]['referencedColumns'][] = $information['REFERENCED_COLUMN_NAME'];
+			}
+		}
+		
+		foreach ($foreignKeys as $keyName => $keyData) {
+			$foreignKeys[$keyName]['columns'] = array_unique($foreignKeys[$keyName]['columns']);
+			$foreignKeys[$keyName]['referencedColumns'] = array_unique($foreignKeys[$keyName]['referencedColumns']);
+		}
+		
+		return $foreignKeys;
+	}
+	
+	/**
+	 * @inheritDoc
+	 */
+	public function getIndexInformation($tableName) {
+		$sql = "SHOW	INDEX
+			FROM	`".$tableName."`";
+		$statement = $this->dbObj->prepareStatement($sql);
+		$statement->execute();
+		$indices = $statement->fetchAll(\PDO::FETCH_ASSOC);
+		
+		$indexInformation = [];
+		foreach ($indices as $index) {
+			if (!isset($indexInformation[$index['Key_name']])) {
+				$type = null;
+				if ($index['Index_type'] === 'FULLTEXT') {
+					$type = 'FULLTEXT';
+				}
+				else if ($index['Key_name'] === 'PRIMARY') {
+					$type = 'PRIMARY';
+				}
+				else if ($index['Non_unique'] == 0) {
+					$type = 'UNIQUE';
+				}
+				
+				$indexInformation[$index['Key_name']] = [
+					'columns' => [$index['Column_name']],
+					'type' => $type
+				];
+			}
+			else {
+				$indexInformation[$index['Key_name']]['columns'][] = $index['Column_name'];
+			}
+		}
+		
+		return $indexInformation;
+	}
+	
 	/**
 	 * @inheritDoc
 	 */
-- 
2.20.1