title: update column collation with laravel
body: <p>I have a <code>case-insensitive</code> collation column in my table.</p>
  
  <pre><code>col_name : hash_id, collation : utf8mb4_unicode_ci
  </code></pre>
  
  <p>I am getting results for <code>yA2JeGs</code> and <code>YA2JeGs</code> when I search for former only.</p>
  
  <p>So I need to update the collation to ensure <code>case-sensitivity</code> for that column.</p>
  
  <p>I tried changing the collation for that column creating a new <code>migration</code> file:</p>
  
  <pre><code>public function up()
  {
      Schema::table('product_match_unmatches', function (Blueprint $table) {
          $table-&gt;string('hash_id')-&gt;collate('utf8mb4_bin')-&gt;change();
      });
  }
  </code></pre>
  
  <p>Also with <code>$table-&gt;string('hash_id')-&gt;collation('utf8mb4_bin')-&gt;change();</code></p>
  
  <p>Migration runs successfully but the collation remains the same.</p>
  
  <p>How do I do that in laravel?</p>