附件和图片不能上传，报如下错误

10:39:10 ERROR: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '2308' for key 'PRIMARY'The sql is: INSERT INTO `zt_file` SET `extension` = 'png',`pathname` = '201605/1210391002704dmb.png',`size` = '60297',`addedBy` = 'leo',`addedDate` = '2016-05-12',`title` = '1210391002704dmb.png' in D:\xampp\zentao\lib\dao\dao.class.php on line 1058, last called by D:\xampp\zentao\lib\dao\dao.class.php on line 583 through function sqlError.

 in D:\xampp\zentao\framework\router.class.php on line 1551 when visiting file-ajaxPasteImage

10:43:42 ERROR: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '2308' for key 'PRIMARY'The sql is: INSERT INTO `zt_file` SET `extension` = 'png',`pathname` = '201605/1210434208013ae1.png',`title` = '字体遮挡',`size` = '200080',`addedBy` = 'jasonshen',`addedDate` = '2016-05-12' in D:\xampp\zentao\lib\dao\dao.class.php on line 1058, last called by D:\xampp\zentao\lib\dao\dao.class.php on line 583 through function sqlError.
 in D:\xampp\zentao\framework\router.class.php on line 1551 when visiting file-ajaxUpload

10:46:20 ERROR: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '2308' for key 'PRIMARY'The sql is: INSERT INTO `zt_file` SET `extension` = 'png',`pathname` = '201605/1210462005501u0m.png',`title` = 'a',`size` = '49071',`addedBy` = 'admin',`addedDate` = '2016-05-12' in D:\xampp\zentao\lib\dao\dao.class.php on line 1058, last called by D:\xampp\zentao\lib\dao\dao.class.php on line 583 through function sqlError.
 in D:\xampp\zentao\framework\router.class.php on line 1551 when visiting file-ajaxUpload

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