title: Updating values in PostgreSQL array
body: <p>I have some columns in PostgreSQL database that are array. I want to add a new value (in UPDATE) in it if the value don't exists, otherwise, don't add anytihing. I don't want to overwrite the current value of the array, but only add the element to it.</p>
  
  <p>Is possible do this in a query or I need to do this inside a function? I'm using PostgreSQL.</p>