PermissionsDao: Add clearForPage()

database/permissionsdaosqlite.cpp

@@ -59,3 +59,16 @@ void PermissionsDaoSqlite::save(std::string pagename, std::string username, Perm
 		throwFrom(e);
 	}
 }
+
+void PermissionsDaoSqlite::clearForPage(std::string pagename)
+{
+	try
+	{
+		auto stmt = *db << "DELETE FROM permissions WHERE page = (SELECT id FROM page WHERE name = ?)" << pagename;
+		stmt.execute();
+	}
+	catch(sqlite::sqlite_exception &e)
+	{
+		throwFrom(e);
+	}
+}