子查询可在MySQL工作台中工作，但不能在PHP中工作

Question

I have a query in MySQL Workbench that works flawlessly when executed. When I run it in PHP on my website, the columns which are sub-queried show up blank.

<?php
 $sql_query = "SELECT PROJECTNOID, ProjectNumber, (SELECT StatusHold FROM 
tblProjectStatus WHERE ProjectStatus = PROJECTSTATUSID), EnteredDate FROM 
tblProjects ORDER BY PROJECTNOID";

I have removed the other four subqueries for simplicity.

 echo $sql_query;
 $resultset = mysqli_query($conn, $sql_query) or die("database error:". 
 mysqli_error($conn));
 while($developer = mysqli_fetch_assoc($resultset)){
 ?>
 <tr id="<?php echo $developer ['PROJECTNOID']; ?>">
 <td><?php echo $developer ['PROJECTNOID']; ?></td>
 <td><?php echo $developer ['ProjectNumber']; ?></td>
 <td><?php echo $developer ['ProjectStatus']; ?></td>
 <td><?php echo $developer ['CustomerProjectLeadID']; ?></td>
 <td><?php echo $developer ['MGEProjectLeadID']; ?></td>
 <td><?php echo $developer ['ProjectStatusNumberID']; ?></td>
 <td><?php echo $developer ['ProjectTitle']; ?></td>
 <td><?php echo $developer ['SubmittedDate']; ?></td>
 <td><?php echo $developer ['StartDate']; ?></td>
 <td><?php echo $developer ['CompletionDate']; ?></td>
 <td><?php echo $developer ['Follow-Up']; ?></td>
 <td><?php echo $developer ['Comments']; ?></td>
 <td><?php echo $developer ['ProjectEnteredBy']; ?></td>
 <td><?php echo $developer ['EnteredDate']; ?></td>
 </tr>
 <?php } ?>

Expected output:

Without The subqueries columns 3,4,5, and 6 would show up with numbers instead.

Answer 1

This is probably because the aliases are missing, eg. try something like :

SELECT PROJECTNOID, ProjectNumber, (SELECT StatusHold FROM 
tblProjectStatus WHERE ProjectStatus = PROJECTSTATUSID) AS StatusHold, EnteredDate FROM 
tblProjects ORDER BY PROJECTNOID

On a second note, it's not very clear what are you trying to achieve but it's better to use joins than sub queries.