搜索MySQL中加密数据的过滤器

Query Description: Let say, I have a database table which stores all users' data in encrypted form. I have a functionality in which the Admin can search the user data. Now the problem is, Admin will enter the normal text in the textbox and I have to filter the user list(on every text change) according to the input of Admin. So meanwhile, I have the bunch of data in encrypted form and I have to filter it on the basis of normal text that Admin enters. Let say, I have a database t