title: Asp.net core how to change Connection String at runtime?
body: <p>I have 2 databases created by a <code>migration</code>. When my project (Asp.net core 2.2) starts, it shows a <code>view</code> that contains a <code>dropdownlist</code> of database names. Now I want any database selected anytime to change the connection string to new database.</p>
  
  <p>I can create 2 connection strings using this <a href="https://stackoverflow.com/questions/37287427/get-multiple-connection-strings-in-appsettings-json-without-ef">link</a>. But I can`t get it to change the connection string at run time.</p>
  
  <p>How can I change connection string at runtime?</p>