title: Laravel merge two columns when querying LIKE
body: <p>I have a search input <code>?search=xxxx</code></p>
  
  <p>I have two columns in my database <code>first_name</code> and <code>last_name</code>.
  I want the search to work for both of them, for example if my input is <code>John Smith</code>
  the search should be like <code>CONCAT(first_name, last_name) ILIKE %input%</code></p>
  
  <p>But laravel doesn't let me do it:</p>
  
  <pre><code>$customers = $customers-&gt;selectRaw("CONCAT('first_name', 'last_name') AS fullname")-&gt;where("fullname", "ilike", "%" . $text . "%");
  </code></pre>
  
  <p>Customers is already defined, and is an ORM object, not collection.</p>
  
  <p>And the error i get for this:</p>
  
  <pre><code>SQLSTATE[42703]: Undefined column: 7 ERROR: column "fullname" does not exist LINE 1: ...) AS fullname from "people" where "type" = $1 and "fullname"... ^ (SQL: select CONCAT('first_name', 'last_name') AS fullname from "people" where "type" = customer and "fullname" ilike %fidel% order by "id" asc)
  </code></pre>
  
  <p>Also tried:</p>
  
  <pre><code> $customers = $customers-&gt;whereRaw("CONCAT('first_name', 'last_name')", "ilike", "%" . $text . "%");
  </code></pre>
  
  <p>And another error:</p>
  
  <pre><code>SQLSTATE[HY093]: Invalid parameter number: parameter was not defined (SQL: select * from "people" where "type" = customer %fidel% CONCAT('first_name', 'last_name') order by "id" asc)
  </code></pre>