In some scenarios allowing select queries against a database can be a security threat. By default all nsurvey administrator can create / change sql based type. 

 

If you create a new user you will need to give him explicitly the rights to create sql based answer type, its strongly recommended that if you dont give sql based answer type right to also remove Xml import rights for the user as a user could change the Xml file and inject his own Sql code.

 

You can also disable the feature for all admin from the web.config by setting the SqlBasedAnswerTypesAllowed to false.