為什么這個jquery ajax調用不從我的PHP腳本返回數據？

Question

我是jQuery的新手，無法在Firebug中調試此Ajax調用：

這是我的ajax電話：

var styndx = $('#studylist option:selected').val();
var studyname = $('#edit_field').val();


$.post("saveStudyName.php", {'type': 'update', 'studyname':studyname, 'styndx':styndx},
    function(resultmsg) {
    $('#edit_field').val('');
    $('#savebtn').attr('disabled',true);
    refresh_studynames();
});

這是函數refresh_studynames：

function refresh_studynames()
{
  $.ajax({                                      
     url: 'getStudyNames.php',                  
     data: "",                                                             
     dataType: 'json',               
          error: function() {
            alert('Refresh of study names failed.');
          },
     success: function(data)
     {
        $data.each(data, function(val, sname) {
        $('#studylist').append( $('<option></option>').val(val).html(sname) )
      });
     } 
  });
}

最后，這是php腳本getStudyNames.php（$ dbname，$ dbconnect，$ hostname都已填充，並且$ dbconnect有效；后端數據庫是Postgres，而pg_fetch_all是PHP中的Postgres函數，它以數組形式返回結果）：

$dbconnect = pg_pconnect("host=".$hostname." user=".$dbuser." dbname=".$dbname);    
    if (!$dbconnect)    {
        showerror(0,"Failed to connect to database",'saveStudyName',30,"username=".$dbuser.", dbname=".$dbname);
        exit;
    }

    $sql = "SELECT ST.studyindex,ST.studyabrv AS studyname
            FROM ibg_studies ST
            ORDER BY studyname";


    $fetchresult = pg_exec($dbconnect, $sql);
    if ($fetchresult) {
        $array = pg_fetch_all($fetchresult);
        echo json_encode($array);
    } else {
        $msg = "Failure! SQL="+$sql;
        echo $msg;
    }

任何幫助，不勝感激....

Answer 1

線

$('#studylist').append( $('<option></option>').val(val).html(sname) );

看起來錯了。

我不太確定，但是您可以嘗試：

var $studylist = $('#studylist').empty();
$data.each(data, function(i, record) {
    $studylist.append( $('<option/>').html(record.sname) );
});