Merge pull request #234 from nextcloud/warning-about-restore

Add a warning for a correct restore

admin_manual/maintenance/backup.rst

@@ -20,6 +20,8 @@ your Nextcloud environment. You could use this command::
 Backup Database
 ---------------
 
+.. warning:: Before restoring a backup see :doc:`restore`
+
 MySQL/MariaDB
 ^^^^^^^^^^^^^
 

admin_manual/maintenance/manual_upgrade.rst

@@ -16,7 +16,7 @@ The other way is by entering your ``config.php`` file and changing
 ``'maintenance' => false,`` to ``'maintenance' => true,``. 
 
 1. Back up your existing Nextcloud Server database, data directory, and 
-   ``config.php`` file. (See :doc:`backup`.)
+   ``config.php`` file. (See :doc:`backup`, for restore information see :doc:`restore`)
 2. Download and unpack the latest Nextcloud Server release (Archive file) from 
    `nextcloud.com/install/`_ into an empty directory outside
    of your current installation.
@@ -81,11 +81,6 @@ Previous Nextcloud Releases
 You'll find previous Nextcloud releases in the `Nextcloud Server Changelog 
 <https://nextcloud.com/changelog/>`_.
 
-Reverse Upgrade
----------------
-
-If you need to reverse your upgrade, see :doc:`restore`.
-
 Troubleshooting
 ---------------
 

admin_manual/maintenance/restore.rst

@@ -30,6 +30,38 @@ install and data folder) to your Nextcloud environment. You could use this comma
 Restore Database
 ----------------
 
+Clean Database Before Restoring
+===============================
+
+.. warning:: Before restoring a backup you need to make sure to delete all existing database tables.
+
+The easiest way to do this is to drop and recreate the database.
+SQLite does this automatically.
+
+MySQL
+^^^^^
+
+MySQL is the recommended database engine. To restore MySQL::
+
+   mysql -h [server] -u [username] -p[password] -e "DROP DATABASE nextcloud"
+   mysql -h [server] -u [username] -p[password] -e "CREATE DATABASE nextcloud"
+
+If you use UTF8 with multibyte support (e.g. for emoijs in filenames), use::
+
+   mysql -h [server] -u [username] -p[password] -e "DROP DATABASE nextcloud"
+   mysql -h [server] -u [username] -p[password] -e "CREATE DATABASE nextcloud CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci"
+
+
+PostgreSQL
+^^^^^^^^^^
+::
+
+    PGPASSWORD="password" psql -h [server] -U [username] -d nextcloud -c "DROP DATABASE \"nextcloud\";"
+    PGPASSWORD="password" psql -h [server] -U [username] -d nextcloud -c "CREATE DATABASE \"nextcloud\";"
+
+Restoring
+=========
+
 .. note:: This guide assumes that your previous backup is called
    "nextcloud-sqlbkp.bak"