Question

我一直在阅读MySQL外键并使用父/子关系表。

下面是表关系（phpmyadmin）。表“dpuchanges”与表“opendpu”，列（ECRNUM）具有外键（PARENT）关系。

出于某种原因，我没有提取任何数据（请参阅下面的php代码）。我在考虑我的SQL语句，但我无法弄清楚它出错的地方。我没有收到任何PHP错误。有人可以帮忙吗？

enter image description here

<!DOCTYPE html>
<html>
<head></head>
<body>
  <table>
  <?php
  require ('config.php');

  $db = null;
  $limit = 10;
  $counter = 0;

  while (true) {
  try {
    $db = new PDO($dsn, $uname, $pword);
    $db->exec( "SET CHARACTER SET utf8" );
    $db->setAttribute( PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC ); 
    $db->setAttribute( PDO::ATTR_PERSISTENT, true );
    break;
  }
    catch (Exception $e) {
        $db = null;
        $counter++;
        if ($counter == $limit)
            throw $e;
    }
  }
$stmt = $db->prepare("SELECT ACTION, PARTNO, ACTIONTXT, REV_WAS, REV_NOW, QTY_FROM, QTY_TO FROM dpuchanges JOIN opendpu ON opendpu.ECRNUM = dpuchanges.PARENT WHERE opendpu.ECRNUM = 82095");
$stmt->execute();
    while ($row = $stmt->fetch(PDO::FETCH_ASSOC)){
            $action=$row["ACTION"];
            $partno=$row["PARTNO"];
            $actiontxt=$row["ACTIONTXT"];
            $rev_was=$row["REV_WAS"];
            $rev_now=$row["REV_NOW"];
            $qty_from=$row["QTY_FROM"];
            $qty_to= $row["QTY_TO"];
?>
<tr>
  <td>Action = <?php echo $action; ?></td>
  <td>PartNo = <?php echo $partno; ?></td>
  <td>Description = <?php echo $actiontxt; ?></td>
  <td>REV WAS = <?php echo $rev_was; ?></td>
  <td>REV NOW = <?php echo $rev_now; ?></td>
  <td>QTY FROM = <?php echo $qty_from; ?></td>
  <td>QTY TO = <?php echo $qty_to; ?></td>
</tr>
<?php } ?>
</table>
</body>
</html>

Answer 1

我认为你不在了;

  <td>Action = <?php echo $action; ?></td>
  <td>PartNo = <?php echo $partno; ?></td>
  <td>Description = <?php echo $actiontxt; ?></td>
  <td>REV WAS = <?php echo $rev_was; ?></td>
  <td>REV NOW = <?php echo $rev_now; ?></td>
  <td>QTY FROM = <?php echo $qty_from; ?></td>
  <td>QTY TO = <?php echo $qty_t; ?></td>

Answer 2

您的数据类型和相关列“dpuchanges.parent”和“openpdu.ecrnum”的 SIZES 必须相同。

来源：http://dev.mysql.com/doc/refman/5.6/en/innodb-foreign-key-constraints.html

PHP MySQL JOIN表，while循环

2 个答案: