title: How to instantiate a DbContext in EF Core
body: <p>I have setup .net core project and db context also. But i cant start using dbContext yet due this error- </p>
  
  <blockquote>
    <p>"there is no argument given that corresponds to the required formal
    parameter 'options'"</p>
  </blockquote>
  
  <p>Controller:</p>
  
  <pre><code>public IActionResult Index()
  {
      using (var db = new BlexzWebDb())
      {
  
      }
      return View();
  }
  </code></pre>
  
  <p>Dbcontext Code:</p>
  
  <pre><code>public class BlexzWebDb : DbContext
  {
      public BlexzWebDb(DbContextOptions&lt;BlexzWebDb&gt; options)
         : base(options)
      { }
  
      public DbSet&lt;User&gt; Users { get; set; }
      public DbSet&lt;Role&gt; Roles { get; set; }
      public DbSet&lt;AssignedRole&gt; AssignedRoles { get; set; }
  
  }
  </code></pre>
  
  <p>error picture attached. Whats the possible fix for that issue?
  Thanks in advance</p>
  
  <p><a href="https://i.stack.imgur.com/d1Px7.png" rel="noreferrer"><img src="https://i.stack.imgur.com/d1Px7.png" alt="pic"></a></p>