if ( isset( $_POST['_search'] ) && $_POST['_search'] == 'true' ) {

    $operations = array(
            'eq' => "= '%s'",            // Equal
            'ne' => "<> '%s'",           // Not equal
            'lt' => "< '%s'",            // Less than
            'le' => "<= '%s'",           // Less than or equal
            'gt' => "> '%s'",            // Greater than
            'ge' => ">= '%s'",           // Greater or equal
            'bw' => "LIKE '%s%%'",       // Begins With
            'bn' => "NOT LIKE '%s%%'",   // Does not begin with
            'in' => "IN ('%s')",         // In
            'ni' => "NOT IN ('%s')",     // Not in
            'ew' => "LIKE '%%%s'",       // Ends with
            'en' => "NOT LIKE '%%%s'",   // Does not end with
            'cn' => "ILIKE '%%%s%%'",    // Contains , case insensitive
            'nc' => "NOT LIKE '%%%s%%'", // Does not contain
            'nu' => "IS NULL OR %s =''", // Is null,
            'nn' => "IS NOT NULL"        // Is not null
    );


    $filters        =   json_decode( $_POST['filters'] ); // this is a result of an ajax call from a jqgrid

    foreach($filters->rules as $filter){

        $searchField    =   $filter->field;
        $searchOperator =   $filter->op;
        $searchString   =   $filter->data; //  the problem is here, it contains htmlentities (Like &nbsp; in my case)