Add database upgrading mechanism for adding the audit table.

Signed-off-by: DL6ER <dl6er@dl6er.de>

advanced/Scripts/database_migration/gravity-db.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+# shellcheck disable=SC1090
+
+# Pi-hole: A black hole for Internet advertisements
+# (c) 2019 Pi-hole, LLC (https://pi-hole.net)
+# Network-wide ad blocking via your own hardware.
+#
+# Updates gravity.db database
+#
+# This file is copyright under the latest version of the EUPL.
+# Please see LICENSE file for your rights under this license.
+
+upgrade_gravityDB(){
+	version=$(sqlite3 "$1" "SELECT "value" FROM "info" WHERE "property" = 'version';")
+	echo $version
+	case "$version" in
+	1)
+		sqlite3 "$1" < "/etc/.pihole/advanced/Scripts/database_migration/gravity/1_to_2.sql"
+		;;
+	esac
+}

advanced/Scripts/database_migration/gravity/1_to_2.sql

@@ -0,0 +1,9 @@
+CREATE TABLE audit
+(
+	id INTEGER PRIMARY KEY AUTOINCREMENT,
+	domain TEXT UNIQUE NOT NULL,
+	date_added INTEGER NOT NULL DEFAULT (cast(strftime('%s', 'now') as int)),
+	comment TEXT
+);
+
+UPDATE info SET value = 2 WHERE property = 'version';

advanced/Templates/gravity.db.sql

@@ -80,13 +80,22 @@ CREATE TABLE gravity
 (
 	domain TEXT PRIMARY KEY
 );
+
+CREATE TABLE audit
+(
+	id INTEGER PRIMARY KEY AUTOINCREMENT,
+	domain TEXT UNIQUE NOT NULL,
+	date_added INTEGER NOT NULL DEFAULT (cast(strftime('%s', 'now') as int)),
+	comment TEXT
+);
+
 CREATE TABLE info
 (
 	property TEXT PRIMARY KEY,
 	value TEXT NOT NULL
 );
 
-INSERT INTO info VALUES("version","1");
+INSERT INTO info VALUES("version","2");
 
 CREATE VIEW vw_gravity AS SELECT domain
     FROM gravity