Embedding wildcard '%' into a query string

[eluser]Unknown[/eluser]
I am doing a search query

Code:

// Prepare query string
//$searchstr = preg_replace('/\s{1,}/', '%', $searchstr);
  
$query = $this->db->select()
->from('employee')
->like("CONCAT(fname,' ',lname)", $searchstr)
->or_like('phone', $searchstr)
->order_by('lname','fname')
->get();

But when I uncomment the preg_replace line, the '%' get escaped in the call. I have tried %% also to no avail.

Any suggestions?