title: how to keep a hash value in the table column in rails
body: <p>i am very new to rails . I am having a table holding all users basic information like</p>
  
  <p><strong>users(id,name,email)</strong>
  now i am trying to keep some additional information of these users in a separate table like</p>
  
  <p><strong>user_details(id,user_id,additional_info)</strong></p>
  
  <p>I have created this user_details table . Now i try to keep some default records for checking . how to keep the hash value of the user's additional details in the additional_info like if my additional details are <strong>user's (designation,salary,prjtname)</strong> in the column additional_info of the User_details table.</p>
  
  <p>Also what <strong>datatype</strong> i have to give for this <strong>additional_info column</strong> of the <strong>User_details</strong> table. Please give some suggestions .. </p>