重新加载同一页面时使用php设置选择选项

Question

I have a php select populated and given a matching value by using php to loop through the results of a sql query.

$result = mysqli_query($con, "select * from course")

echo "<form action='' method='post'>";
echo "<select name='CourseSelect'>";
echo "<option value='0'> - Select Course - </option>";
while($row = mysqli_fetch_array($result))
{
 echo "<option value='" . $row['Title'] ." '>" . $row['Title'] . "</option>";
}

echo "</select>";
echo "<input name='SubmitCourse' type='submit'>";
echo "</form>";

That gives me a drop down list populated with all course titles, upon submission I can access the selected value using $_POST['CourseSelect'];

However the drop down (select) resets itself to the default value when the page reloads.

How can I keep that option selected using php?

I know that I can use the selected keyword inside of an a select option to make that option the default selected option.

for example the second option would be selected when loading the page:

<select>
<option>One</option>
<option selected>Two</option>
<option>Three</option>
</select>

Answer 1

You can make it simple as

while($row = mysqli_fetch_array($result))
{
 $select = '';
 if( isset($_POST['CourseSelect']) && $_POST['CourseSelect'] == $row['Title'] ) $select = 'SELECTED';
 echo "<option value='".$row['Title']."' ".$select.">" . $row['Title'] . "</option>";
}