Handling loops and combining values in PHP - php

Question

I have a table like this.
author_id author_state author_name
1 CA Hello
2 MI World
3 CA How
4 MI Are
Please let me know how can I achieve this. In other words, I should loop it and combine the state values first and display the details.
Here is my PHP Code
<table>
<tr><td>Author ID</td><td>Author State</td><td>Author Name</td></tr>
<?php
$row_data = mysql_query("select * from author" );
while($row = mysql_fetch_array($row_data) ) {
?>
<tr>
<td><?php echo $row['author_id']; ?></td>
<td><?php echo $row['author_state']; ?></td>
<td><?php echo $row['author_name']; ?></td>
</tr>
<?php } ?>
</table>
My Expected output is to combine the state and display something like below:
Author ID Author Name
=======================================
CA
==
1 Hello
3 How
MI
==
2 World
4 Are

Answer 1

You can do this fairly easily, by sorting your output by author_state, and using a variable to keep track of which state you're outputting. If the state changes, then you simply output the state as a new header.
You can take advantage of the SQL order by clause so that you don't have to sort the data yourself.
Here is an edit of your code, where I've simply added the order by to your mysql_query(), and added a variable for $current_state.
<table>
<tr><td>Author ID</td><td>Author State</td><td>Author Name</td></tr>
<?php
$current_state = "";
$row_data = mysql_query("select * from author order by author_state" );
while($row = mysql_fetch_array($row_data) ) {
// Output the "new" state
if ($row['author_state'] != $current_state)
{
echo "<tr><td colspan=\"3\">{$row['author_state'}}</td></tr>";
$current_state = $row['author_state'];
}
?>
<tr>
<td><?php echo $row['author_id']; ?></td>
<td><?php echo $row['author_state']; ?></td>
<td><?php echo $row['author_name']; ?></td>
</tr>
<?php } ?>
</table>
As a side note, I would strongly encourage you to look into using mysqli or PDO instead of the mysql_* functions. The mysql_* functions are only availble in very old versions of PHP (they were completely removed in PHP7).