title: Using assign() with an unknown variable
body: <p>I have a Shiny dashboard app where the user inputs their name into a text box.</p>
  
  <p>The dashboard then reads in the users dataset after retrieving the data from a connected database and assigns it to a variable that includes their user name </p>
  
  <p>Example</p>
  
  <pre><code>assign(paste0(input$user_name, "_dataset"), 
         sqlQuery(connectionString, str_paste("Select * from ",user_name,"_table;"))
         )
  
  </code></pre>
  
  <p>Question: Without knowing <code>input$user_name</code> how can I refer to the variable when preparing plots and charts from the data?</p>
  
  <p>I tried this,</p>
  
  <pre><code>plot_ly(paste0(input$user_name, "_dataset"), x = ..., y = ... etc)
  </code></pre>
  
  <p>but it does not work.</p>