PHP中的重复列

Question

$course = mysql_query('SELECT cc.name, c.fullname FROM mdl_course WHERE cc.id = c.id');

echo '<table>';
while($row = mysql_fetch_array($course))
{
     $categoryname = $row['name'];
     $coursename   = $row['fullname'];
     echo '<tr><td>$categoryname</td>
               <td>$coursename</td>
           </tr>
}
echo '</table>';

I want the category name to display only once ie, it shouldn't repeat

Answer 1

Some possible answers are already given. My idea was to keep a counter variable too to check and see if it is the first iteration. If so, then show the category name.

But besides of that i really think you should re-check your database design. Why does multiple rows have the same category name? That is wrong in terms of database design. The category should be in a sepparate table.

That way you can loop through the categories first, echo the category name, then loop through the mdl_course table and get all the rows where the pk_category_id equals the fk_category_id from the mdl_course table.

Example:

$cats = query ("SELECT pk_category_id, name FROM categories");
while ( $cat_row = mysql_fetch_row($cats) )
{
    echo $cat_row['name'];

    $cats = query ("SELECT cols, you, need FROM mdl_course WHERE fk_category_id = '".$cat_row['pk_category_id']."'");
    while ( $mdl_row = mysql_fetch_row($cats) )
    {
        echo 'other data';
    }
}

Answer 2

You should add a temp var to save the previous category name, and print it only if it has changed. Note: this solution assumes your query results are grouped by categoryname

Like this:

$course = mysql_query('SELECT cc.name, c.fullname FROM mdl_course WHERE cc.id = c.id');

echo '<table>';
$prev_name = ''; //temp var
while($row = mysql_fetch_array($course))
{
     $categoryname = $row['name'];
     $coursename   = $row['fullname'];
     echo '<tr><td>'.($prev_name != $categoryname ? $categoryname : '').'</td>
               <td>$coursename</td>
           </tr>';
     $prev_name = $categoryname; //temp var assignment
}
echo '</table>';

this snippet will check if the category name has changed, and give an appropriate output (the new category name or an empty string):

($prev_name != $categoryname ? $categoryname : '')