diff --git a/tools/tables.sql b/tools/tables.sql
index b252cee..c9f76f2 100644
--- a/tools/tables.sql
+++ b/tools/tables.sql
@@ -35,17 +35,17 @@ CREATE TABLE IF NOT EXISTS `tasks` (
 CREATE TABLE IF NOT EXISTS `tasklogs` (
   `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
   `pid` int(10) NOT NULL,
-  `title` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
-  `content` text COLLATE utf8_unicode_ci NOT NULL,
-  `caty` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
-  `priority` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
-  `department` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
-  `status` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
-  `tag` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
-  `pro` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
-  `leader` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
-  `tester` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
-  `changer` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
+  `title` varchar(255) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
+  `content` text COLLATE utf8_unicode_ci,
+  `caty` varchar(255) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
+  `priority` varchar(255) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
+  `department` varchar(255) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
+  `status` varchar(255) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
+  `tag` varchar(255) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
+  `pro` varchar(255) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
+  `leader` varchar(255) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
+  `tester` varchar(255) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
+  `changer` varchar(255) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
   `deadline` int(11) NOT NULL DEFAULT '0',
   `created_at` timestamp,
   PRIMARY KEY (`id`),