“通知”;未定义索引“;当运行MySQL查询时


Notice "undefined index" when running MySQL query

我是编程新手。你能帮我把MySQL中的数据放到PHP列表/菜单中吗?

<tr>
    <td align="right">Owners Name</td>
    <td>
        <select name="owners" id="owners">
            <?php 
            $owners = mysql_real_escape_string($_POST['owners']);
            $sql = mysql_query("SELECT lld_Lname,lld_Fname FROM landlords "); 
            while ($row = mysql_fetch_array($sql))
            {
            ?> 
            <option <?php echo $_POST['owners']==$row['owners'] ? 'selected' : ''?>><?php echo $row['owners'] ?></option> 

            <?php 
            } 
            ?> 
        </select>
    </td>
</tr>

运行以上代码后,我得到了这个错误:

注意:未定义索引:c:''wamp''www''real_estate''admin''add_building.php online 41 中的所有者

只需打印$row并检查所有数据都已提取。检查[所有者]是否存在(在您的情况下为否),然后继续进行比较

    <?php 
    $owners = mysql_real_escape_string($_POST['owners']);
    $sql = mysql_query("SELECT owners FROM landlords ") or die(mysql_error());
    ?>
    <tr> 
    <td align="right">Owners Name</td> 
    <td><select name="owners" id="owners">
        <?php
        while ($row = mysql_fetch_array($sql)) { ?> 
        <option <?php echo $_POST['owners']==$row['owners'] ? 'selected' : ''?>><?php echo $row['owners'] ?></option> 
        <?php } ?> 
        </select>
    </td>
    </tr>

如果DB表中的owners列可用,这可能会起作用,或者发布您正在获得的错误