Php 如果列为空，则显示回显，否则显示另一个回显

我写了这段代码，但有一些错误，它只显示第一个回声，即使列不是空的

  <?php

  include_once 'dbconnect.php';

   // Create connection
  $conn = new mysqli(DBHOST,DBUSER,DBPASS,DBNAME);
// Check connection
if ($conn->connect_error) {
 die("Connection failed: " . $conn->connect_error);
}  

$sql= ("SELECT subuser1 FROM users WHERE id=".$_SESSION['user']  );
$result = $conn->query($sql);


$subuser1 = $row["subuser1"];


if ($result->num_rows > 0) {

if (empty($subuser1)) {

echo "subuser1 is either 0, empty, or not set at all";
}
 } else {
echo " subuser1 not empty";

如果subuser1列为空，我将调用代码以显示echo“1” 如果列subuser1不是空的，则显示echo“2”

  <?php

  include_once 'dbconnect.php';

   // Create connection
  $conn = new mysqli(DBHOST,DBUSER,DBPASS,DBNAME);
// Check connection
if ($conn->connect_error) {
 die("Connection failed: " . $conn->connect_error);
}  

$sql= ("SELECT subuser1 FROM users WHERE id=".$_SESSION['user']  );
$result = $conn->query($sql);


$subuser1 = $row["subuser1"];


if ($result->num_rows > 0) {

if (empty($subuser1)) {

echo "subuser1 is either 0, empty, or not set at all";
}
 } else {
echo " subuser1 not empty";

---

我这样解决它，如果有人需要它，它就可以完美地工作

 <?php
 $userR= 0 ;
 include_once 'dbconnect.php';

 // Create connection
 $conn = new mysqli(DBHOST,DBUSER,DBPASS,DBNAME);
 // Check connection
if ($conn->connect_error) {
 die("Connection failed: " . $conn->connect_error);
}  

$sql= ("SELECT * FROM users WHERE id=".$_SESSION['user']  );
$result = $conn->query($sql);

if ($result->num_rows > 0) {

 while($row = $result->fetch_assoc()) {  

  if ($row["subuser1"] == NULL ){
 echo "";  }
   else {

echo " bla bla bla "
}
}
?>


if（$subuser1==NULL | |$subuser1==“”| |$subuser1==“0”）很抱歉它不工作它不显示任何不工作的东西我不知道你的其他问题是什么，但你的代码中没有
$row
：
$row=$result->mysqli\u fetch assoc（）祝你好运。结束语
}
也丢失了。