h1>CDbException</h1>
<p>CDbCommand failed to execute the SQL statement: SQLSTATE[42S21]: Column already exists: 1060 Duplicate column name 'attribute_cpdb_3'. The SQL statement executed was: ALTER TABLE lime_tokens_556849 ADD COLUMN attribute_cpdb_3 VARCHAR(255) (C:\xampp\htdocs\limesurvey_yii\framework\db\CDbCommand.php:516)</p><pre>#0 C:\xampp\htdocs\limesurvey_yii\framework\db\CDbCommand.php(355): CDbCommand->queryInternal('', 0, Array)
#1 C:\xampp\htdocs\limesurvey_yii\application\models\Participants.php(1140): CDbCommand->query()
#2 C:\xampp\htdocs\limesurvey_yii\application\controllers\admin\participantsaction.php(1605): Participants->copytosurveyatt('556849', '', Array, ',7a6c6919-41c8-...')
#3 [internal function]: participantsaction->addToTokenattmap()
#4 C:\xampp\htdocs\limesurvey_yii\application\controllers\admin\participantsaction.php(18): call_user_func_array(Array, Array)
#5 C:\xampp\htdocs\limesurvey_yii\application\controllers\admin\participantsaction.php(23): participantsaction->route('addToTokenattma...')
#6 [internal function]: participantsaction->run('addToTokenattma...')
#7 C:\xampp\htdocs\limesurvey_yii\framework\web\actions\CAction.php(104): ReflectionMethod->invokeArgs(Object(participantsaction), Array)
#8 C:\xampp\htdocs\limesurvey_yii\framework\web\actions\CAction.php(70): CAction->runWithParamsInternal(Object(participantsaction), Object(ReflectionMethod), Array)
#9 C:\xampp\htdocs\limesurvey_yii\framework\web\CController.php(300): CAction->runWithParams(Array)
#10 C:\xampp\htdocs\limesurvey_yii\framework\web\CController.php(278): CController->runAction(Object(participantsaction))
#11 C:\xampp\htdocs\limesurvey_yii\framework\web\CController.php(257): CController->runActionWithFilters(Object(participantsaction), Array)
#12 C:\xampp\htdocs\limesurvey_yii\application\controllers\AdminController.php(97): CController->run('participants')
#13 C:\xampp\htdocs\limesurvey_yii\framework\web\CWebApplication.php(277): AdminController->run('participants')
#14 C:\xampp\htdocs\limesurvey_yii\framework\web\CWebApplication.php(136): CWebApplication->runController('admin/participa...')
#15 C:\xampp\htdocs\limesurvey_yii\framework\base\CApplication.php(158): CWebApplication->processRequest()
#16 C:\xampp\htdocs\limesurvey_yii\index.php(171): CApplication->run()
#17 {main}</pre>