Cannot connect rows in html with php (logical error display) - php

Question

The html table rows aren't displayed properly. I want to combine the two while loops in the table row but sadly the Update and Delete button are not arranged properly.
here's my code I used two queries that's why it has two while loops
$sql_sel=mysql_query("SELECT students.stud_id, students.fname, students.lname, students.gender, subjects.sub_code, subjects.subject_name FROM students, enrollments, subjects WHERE students.stud_id = enrollments.stud_id and subjects.sub_code = enrollments.sub_code");
$sql_sel1=mysql_query("SElECT * FROM enrollments");
while($row=mysql_fetch_array($sql_sel)) //for the first query
{
$i++;
$color=($i%2==0)?"lightblue":"white";
?>
<tr bgcolor="<?php echo $color?>">
<td><?php echo $i;?></td>
<td><?php echo $row['stud_id'];?></td>
<td><?php echo $row['fname']." ".$row['lname'];?></td>
<td><?php echo $row['gender'];?></td>
<td><?php echo $row['sub_code'];?></td>
<td><?php echo $row['subject_name'];?></td>
<?php
while($row=mysql_fetch_array($sql_sel1)) //for the second query
{ <!-------The Update and Delete Button are not displayed properly------>
?>
<td align="center"><img src="picture/update.png" /></td>
<td align="center"><img src="picture/delete.png" /></td>
<?php
}
?>
</tr>
<?php
}
?>
Here is the visual scenario of the problem:
The desired output must be like this:

Answer 1

In table header use colspan='4' for the last column.
Also be sure that you fill the table with empty columns, where you don't have information to fill with.
Edit 1:
Sorry, I haven't seen what's really the problem was. Here should be the working code:
while($row=mysql_fetch_array($sql_sel))
{
$i++;
$color=($i%2==0)?"lightblue":"white";
?>
<tr bgcolor="<?php echo $color?>">
<td><?php echo $i;?></td>
<td><?php echo $row['stud_id'];?></td>
<td><?php echo $row['fname']." ".$row['lname'];?></td>
<td><?php echo $row['gender'];?></td>
<td><?php echo $row['sub_code'];?></td>
<td><?php echo $row['subject_name'];?></td>
<!-- You were already in a while loop -->
<td align="center"><img src="picture/update.png" /></td>
<td align="center"><img src="picture/delete.png" /></td>
</tr>
<?php
}
?>
As you can see you were already in a while loop, and the second one was unnecesary.
Edit 2:
There is a single SQL query now:
<?php
// UPDATED SQL QUERY
$sql_sel = mysql_query("SELECT students.stud_id, students.fname, students.lname, students.gender, subjects.sub_code, subjects.subject_name, enrollments.enroll_num
FROM students, enrollments, subjects
WHERE students.stud_id = enrollments.stud_id and subjects.sub_code = enrollments.sub_code");
while($row = mysql_fetch_array($sql_sel)){
$i++;
$color=($i%2==0)?"lightblue":"white";
?>
<tr bgcolor="<?php echo $color?>">
<td><?php echo $i;?></td>
<td><?php echo $row['stud_id'];?></td>
<td><?php echo $row['fname']." ".$row['lname'];?></td>
<td><?php echo $row['gender'];?></td>
<td><?php echo $row['sub_code'];?></td>
<td><?php echo $row['subject_name'];?></td>
<td align="center"><img src="picture/update.png" /></td>
<td align="center"><img src="picture/delete.png" /></td>
</tr>
<?php
}
?>
Why it didn't worked?
You were reading the whole informations for every student. Then you were reading the whole informations in enrollments table.
You started writing the first row with student information, and inside it you told the server to start writing all the information he had regarding enrollments (without even be linked to that student's id).
When the server reached the second row, all the information available for enrollments were depleted.
Now you have them linked in your first query. Please ask in comments if you need further explanations.

Answer 2

Try this,
$sql= "SELECT sts.stud_id, sts.fname, sts.lname, sts.gender, sub.sub_code, sub.subject_name, ets.enroll_num
FROM students sts
JOIN enrollements ets ON(sts.stud_id = ets.stud_id)
JOIN subjects sub ON (sub.sub_code = ets.sub_code)
GROUP BY sts.stud_id, sub.sub_code";
$sql_sel=mysql_query($sql);
while($row=mysql_fetch_array($sql_sel)) //for the first query
{
$i++;
$color=($i%2==0)?"lightblue":"white";
?>
<tr bgcolor="<?php echo $color?>">
<td><?php echo $i;?></td>
<td><?php echo $row['stud_id'];?></td>
<td><?php echo $row['fname']." ".$row['lname'];?></td>
<td><?php echo $row['gender'];?></td>
<td><?php echo $row['sub_code'];?></td>
<td><?php echo $row['subject_name'];?></td>
<td align="center"><img src="picture/update.png" /></td>
<td align="center"><img src="picture/delete.png" /></td>
</tr>
<?php
}
?>
I have added enroll_num column in select, And you dont need two queries for this. One query with proper join will be fine.