Question

这个令我困惑。我有两个不同的mySQL表我需要从中提取信息，我正在创建一个html下拉列表并尝试从变量中填充值。它第一次通过循环，但不是在那之后。我收到警告（查看HTML时）：

b>Warning</b>:  array_combine() expects parameter 1 to be array, integer given in <b>/MY URL</b> on line <b>56</b><br />
<br />

更容易显示代码，所以这里是：

$UserID = "118";
$UndefinedEvents = array();
$EventDates = array();
$UserTimelines = array();


  $query = "SELECT * FROM  events  WHERE UserID='$UserID' AND ParentEventID IS NULL";
  $result = mysql_query($query);

  $query2 = "SELECT * FROM  timelines  WHERE UserID='$UserID'";
  $result2 = mysql_query($query2);

  //Getting the Timeline names and their IDs
  while($row = mysql_fetch_array($result2))
    {
    $UserTimelines[] = $row['TimeLineName'];
    $TimelineID[] = $row['TimeLineID'];
    }

  //Getting and events that have a NULL value   
  while($row = mysql_fetch_array($result))
  {
    echo $row['UserID'] . " ".$row['EventName']. " " . $row['ParentEventID'];
    $UndefinedEvents[] = $row['EventName'];
    $EventDates[] = $row['StartDate'];
  }

  //Iterating through events with NULL value and telling user which events are NULL
  foreach (array_combine($UndefinedEvents, $EventDates) as $event=>$dates){
    echo "This Event does not have a Timeline associated with it: " .$event . " on ".$dates. '<br>';
  echo "Choose a Timeline:<br>";
  ?>

  <select>

  //THIS IS LINE 56:  Iterating through the timelines and creating a dropdown for the user to choose a timeline.
  <?php foreach (array_combine($TimelineID, $UserTimelines) as $TimelineID=>$timeline){ 
        echo "<option value=".$TimelineID."> ".$timeline. "</option>";

  }
  echo " </select><br><br>";
  }
  ?>

  <?php
    mysql_close($con);  
?>

就像我说的那样，它适用于第一个循环，并且正确地将值放入，但是每个循环之后都会产生上述警告。

Answer 1

在你的第二个foreach中，你覆盖了$TimelineID变量：

foreach (array_combine($TimelineID, $UserTimelines) as $TimelineID=>$timeline){

只需使用其他内容：

foreach (array_combine($TimelineID, $UserTimelines) as $temp_TimelineID=>$timeline){

Answer 2

只是为了检查......在这段代码中，您从一行获取ID和名称，并将它们分成两个独立的数组......

//Getting the Timeline names and their IDs
while($row = mysql_fetch_array($result2))
  {
    $UserTimelines[] = $row['TimeLineName'];
    $TimelineID[] = $row['TimeLineID'];
  }

...然后您将这些数组组合在一起以生成选项值/描述？

为什么不在数组的一个元素（数组数组）中的每一行存储两个值？或使用关联数组 - 以id作为键，文本作为值？（或者更好的是，将行映射到对象）

http://php.net/manual/en/language.types.array.php

我究竟做错了什么？使用foreach循环为<option> </option>输入值字段

2 个答案: