php - Mysql getting json from nested queries -

i had 2 tables whch visitormaster , visitor comment. visitor master has unique visitorid , comment bt visitor stores in visitorcomment using visitorid foreign key there. want data in following format:

[     {         "visitorid":1,         "visitorname":"abc",         "comment":                 {                     "commentid":2;                     "comment":"xyz"                 }     }     {         "visitorid":2,         "visitorname":"lmn",         "comment":                 {                     "commentid":4;                     "comment":"mno"                 }     }  ]  $sql = mysql_query("select * visitormaster"); if(mysql_num_rows($sql) > 0) {     $result = array();     while($rlt = mysql_fetch_array($sql,mysql_assoc))     {         $result[] = $rlt[];         $vid=$rlt["visitorid"];         $sql1 = mysql_query("select * visitorcomment visitor_id = "."'$vid'");         while($rltcomment = mysql_fetch_array($sql1,mysql_assoc))         {             $commentresult[] = $rltcomment[];         }         $newresult=array($result,"comment"=>$rltcomment[0]);     }     $array=array("result_data"=>$newresult);     $this->response($this->json($array), 200); } 

but there no output.

quote missing in sql statement mysql_query("select * visitormaster);

to see errors use ini_set("display_errors","on"); turn error reporting on. give errors.