json_encode用法

$query=mysql_query($SQL);
 while($row = mysql_fetch_array($query)){
        $xdata[]=$row['EventDate'];
         $ydata[]=intval($row['data']);
    }

  $data_arr=array($xdata,$ydata）

  json_encode($data_arr);

$.ajax({
   type: "Get",  
   url: "columndata.php?r=" + Math.floor(Math.random() * 1000 + 1),
   data: { 'BeginTime': "" + beginTime + "", "EndTime": "" + endTime + "" , "keyword": "" + keyword + "" },
   dataType: "text",  
   global: false, 
   async: false,  
   success: function (strReult) {
    if (strReult == "-1") { alert("fail!"); return; }
            
 

   },
   error: function () {
    alert("fail!");
   }
  });