Lecture_ID | Subject | Section | time_Date

0001       | Maths   |  A      | ....
0002       | Maths   |  B      | ....
0003       | Maths   |  C      | ....
0004       | Maths   |  B      | ....

Section A
time_Date
time_Date

Section B
time_Date
time_Date
...

$query = 'SELECT * FROM Lecutre_info WHERE Subject="'.$_GET['subject'].'" ORDER BY Section ASC';
$result = mysql_query($query) or die(mysql_error());

while($row = mysql_fetch_array($result)) {

print '<h1>'.$row['Section']
print '<br>'.$row['time_Date'];

}