首页 > 解决方案 > forech 显示比数据库少一行

问题描述

我有一个 if 语句,如果我的表中存在某种条件,它会动态显示 html,其中包含数据库中存在的每一行的数据,我正在使用 foreach 循环,但它在行上显示的内容少于其中的内容实际的表,如果它有三行,它会显示两行,如果只有一行它什么也不显示,它会通过 if 语句,因为如果它不显示错误消息,但在我的情况下它只是显示一个空白页面,为什么会这样?

function show()
{
   
    $stmt = $this->db->prepare("SELECT offered_rides.*, reg.*
                                FROM offered_rides
                                 JOIN reg ON offered_rides.phone = reg.phone where 
                                 offered_rides.date = :date AND offered_rides.seats >= :seats AND offered_rides.start = :start AND offered_rides.finish = :finish ");
    $stmt->bindParam(':date',$this->date);
    $stmt->bindParam(':seats',$this->seats);
    $stmt->bindParam(':start',$this->from);
    $stmt->bindParam(':finish',$this->to);
    $stmt->execute();
    $row = $stmt->fetch(PDO::FETCH_ASSOC);
    
    
    
   if($row)   
   { 
           
      foreach($stmt as $row):
            
          
         ?>

        <form action="Update.php" method="POST">
            
            <div class="a">
                
                <div class="fnamelname">
                <p style="display:inline;"> <?php echo $row["fname"];?>  </p>
                <p style="display:inline;"> <?php echo $row["lname"];?> </p>
                </div>
                    
            </div>
                
            
            //i need to store these to use them later
            <input type = "hidden" name = "phone-D" value = "<?=$row['phone'] ?>" />
            <input type = "hidden" name = "time" value = "<?= $row['time'] ?>" />
            <input type = "hidden" name = "seats" value = "<?= $row['seats'] - $this->seats?>" />
             
            
        </form>

        <?php endforeach; 
        
        
   }    

标签: phphtmlpdo

解决方案


这完全没有意义:foreach($stmt as $row):. $stmt不是数组,它是单个对象。相反,您应该使用以步骤为条件的while循环。$row = $stmt->fetch(PDO::FETCH_ASSOC);因为该fetch()方法每次调用时都会返回一行。这就是你想要的。

function show() {
   
    $stmt = $this->db->prepare("SELECT offered_rides.*, reg.* FROM offered_rides JOIN reg ON offered_rides.phone = reg.phone WHERE  offered_rides.date = :date AND offered_rides.seats >= :seats AND offered_rides.start = :start AND offered_rides.finish = :finish ");
    $stmt->bindParam(':date',$this->date);
    $stmt->bindParam(':seats',$this->seats);
    $stmt->bindParam(':start',$this->from);
    $stmt->bindParam(':finish',$this->to);
    $stmt->execute();


    while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
        ?>

        <form action="Update.php" method="POST">                
            <div class="a">
                <div class="fnamelname">
                <p style="display:inline;"> <?php echo $row["fname"];?>  </p>
                <p style="display:inline;"> <?php echo $row["lname"];?> </p>
                </div>
            </div>
            //i need to store these to use them later
            <input type = "hidden" name = "phone-D" value = "<?=$row['phone'] ?>" />
            <input type = "hidden" name = "time" value = "<?= $row['time'] ?>" />
            <input type = "hidden" name = "seats" value = "<?= $row['seats'] - $this->seats?>" />
        </form>

        <?
    }
}

和一个提示:当在 php 中以相应的方式使用“短标签”时,你的 html 标记会更容易阅读:

        <form action="Update.php" method="POST">                
            <div class="a">
                <div class="fnamelname">
                <p style="display:inline;"><?= $row["fname"]?></p>
                <p style="display:inline;"><?= $row["lname"]?></p>
                </div>
            </div>
            //i need to store these to use them later
            <input type="hidden" name="phone-D" value="<?=$row['phone']?>"/>
            <input type="hidden" name="time" value="<?= $row['time']?>"/>
            <input type="hidden" name="seats" value="<?= $row['seats'] - $this->seats?>"/>
        </form>

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