Question

如何使用php检查表中的空行？

我尝试使用此代码，但它不起作用：

<?php
ob_start();
session_start();
require 'connection/config.php';
$id = $_GET['id'];
echo $id;
$userid = $_SESSION['userid'];
$sql = "select * from post where id='$id'";
//echo $sql;
$result1 = mysqli_query($conn, $sql);
while ($row1 = mysqli_fetch_array($result1)) {
  echo $row1['message'] . "<br>";
  $_SESSION['pid'] = $row1['id'];
  $userid = $_SESSION['userid'];
  echo $userid;
  $a = $row1['id'];
  $sql = "select * from post inner join likenew on post.id=likenew.postid where likenew.postid='$id' and likenew.userid='$userid'";
  $result = mysqli_query($conn, $sql);
  while ($row = mysqli_fetch_array($result)) {
    if (empty($row)) { ? >
      < a href = "ative.php?id=<?php echo $row['id'];?>" > ready < /a><?php
    } else { ? >
      < a href = "deactive.php?id=<?php echo $row['id'];?>" > notready < /a><?php
    }
  }
}

Answer 1

你不想使用while循环查找行数，就像这样使用。

$sql="select * from post inner join likenew on post.id=likenew.postid where likenew.postid='$id' and likenew.userid='$userid'";
$result=mysqli_query($conn,$sql);
$num=mysqli_num_rows($result)
if($num==0){
    ?> <a href="ative.php?id=<?php echo $row['id'];?>">ready</a> <?php
}else{
    ?> <a href="deactive.php?id=<?php echo $row['id'];?>">notready</a><?php
}

Answer 2

$row = mysqli_fetch_array($result);

if(isset($row['description'])) {
    echo "<p>No description</p>";
} else {
    echo '<p>'.$row['description'].'</p>';
}

Answer 3

这是一个例子

$sql = "SELECT fname, lname, mname FROM sks_staffs where id = '$a'";
$query = $this->db->query($sql);
  if ($query->num_rows() == 0) 
{
   // Do something
}

这将有效

如何检查表中的空行

3 个答案: