displaying php mysql query result with one to many relationship

Question

Heres A Sample Table:

info table
info_id     name  
1           john  
2           peter
------------------------  
details table  
details_id      log                               date  
1            test log for john                  2013-08-01  
1            another log for john               2013-08-02  
2            test log for peter                 2013-08-02

Here's my Sample Query:

SELECT info.info_id, info.name, details.details_no, details.log, details.date 
FROM info JOIN details ON details.details_id = info.info_id 
GROUP BY info.info_id  

And Here's display i want to achieve:

john  
1     test log for john            2013-08-01  
1     another test log for john    2013-08-02  

peter  
2     test log for peter           213-08-02  

I have tried using foreach loop and then execute another foreach loop inside the first loop.

Please Help Guys

Answer 1

Try making your results into a multidimensional array like below

Note: I am assuming that details.details_no is a primary key for the details table and you want results similar to

john  
1     test log for john            2013-08-01  
2     another test log for john    2013-08-02  

peter  
3     test log for peter           213-08-02

Which you can retrieve with the following

...
$qry = "
    SELECT
        info.info_id,
        info.name,
        details.details_no,
        details.log,
        details.date 
    FROM
        info
        JOIN details ON (details.details_id = info.info_id)
";
$result = mysqli_query($your_db_link,$qry)
$data = array();
while($row = mysqli_fetch_array($result)){
    $data[$row["info_id"]]["name"] = $row["name"];
    $data[$row["info_id"]]["logs"][$row["details_no"]] = array(
        "log"=>$row["log"],
        "date"=>$row["date"],
    );
}

Would result in an array like:

$data = array(
    "1" => array(
        "name" => "john",
        "logs" => array(
            "1" => array(
                "log" => "test log for john",
                "date" => "2013-08-01",
            ),
            "2" => array(
                "log" => "another test log for john",
                "date" => "2013-08-02",
            ),
        ),
    ),
    "2" => array(
        "name" => "peter",
        "logs" => array(
            "3" => array(
                "log" => "test log for peter",
                "date" => "2013-08-02",
            ),
        ),
    ),
);

Then you could display like:

echo "<table>";
foreach($data as $value){
    echo "<tr><td colspan='3'>".$value["name"]."</td></tr>";
    foreach($value["logs"] as $subkey => $subvalue){
        echo "<tr>";
        echo "<td>".$subkey."</td>";
        echo "<td>".$subvalue["log"]."</td>";
        echo "<td>".$subvalue["date"]."</td>";
        echo "</tr>";
    }
}
echo "</table>";

Which would result similar to:

<table>
    <tr>
        <td colspan='3'>john</td>
    </tr>
    <tr>
        <td>1</td>
        <td>test log for john</td>
        <td>2013-08-01</td>
    </tr>
    <tr>
        <td>2</td>
        <td>another test log for john</td>
        <td>2013-08-02</td>
    </tr>
    <tr>
        <td colspan='3'>peter</td>
    </tr>
    <tr>
        <td>3</td>
        <td>test log for peter</td>
        <td>2013-08-02</td>
    </tr>
</table>

Answer 2

You are probably going to have to take the data and make the array that you want.

$data = array();
foreach ($result as $item) {
    $key = $item['name']; // or $item['info_id']
    if (!isset($data[$key])) {
        $data[$key] = array();
    }

    $data[$key][] = $item;
}

// Build your table with the new $data array

EDIT

This is just an example. As amaster507 points out, if your name field isn't unique, you will need to build your array on a unique key. Not terribly different from this, as you could probably just change instances of $item['name'] to $item['info_id'] .

Answer 3

Ok, first an explanation of the problem.

When you use GROUP BY , you no longer get every result as a row, but instead, you get 1 row with grouped content, that is, you can use GROUP BY to get something like the concatenation of both log cells from john, for example.

To do what you want, remove the GROUP BY to get all the rows, and then manually process them.

I recommend you to make easy the job, to use underscore.php which has a function called groupBy which will return an array grouped in subarrays, based on this case, the info_id column.

It will be used something like this:

$array_with_all_the_rows = $query->fetchAll(); // Or whatever you use to get all rows in 1 array.
$grouped_array = __::groupBy($array_with_all_the_rows, 'info_id');

That grouped array will be like this:

$grouped_array = Array( 
    "1" => Array(
        "info_id"=> "1", "log"=>"test log for john", "date" => "2013-08-01",
        "info_id"=> "1", "log"=>"another test log for john", "date" => "2013-08-02"
    ), 
    "2" => Array(
        "info_id"=> "2", "log"=>"test log for peter", "date" => "2013-08-02"
    )
)

Answer 4

To refine Ascherer's answer, you don't need to declare arrays before pushing data into them with [] syntax. If you were using array_push() the array would need to be declared as a variable first.

With MySQLi, you can iterate the result set object directly with a foreach() and unconditionally use the info_id values as keys to group by.

$sql = "SELECT info.info_id,
               info.name,
               details.log,
               details.date
        FROM info
        JOIN details ON details.details_id = info.info_id
        ORDER BY info.info_id";

$result = [];
foreach ($mysqli->query($sql) as $row) {
    $data[$row['info_id']][] = $row;
}

With PDO, you can use ->fetchAll(PDO::FETCH_GROUP) to create the same output without manually looping.

When generating your html markup...

<table>
    <?php foreach ($result as $groupId => $rows) { ?>
        <tr>
            <td colspan='3'><?php echo $rows[0]["name"]; ?></td>
        </tr>
        <?php foreach($rows as $row) { ?>
            <tr>
                <td><?php echo $groupId; ?></td>
                <td><?php echo $row['log']; ?></td>
                <td><?php echo $row['date']; ?></td>
            </tr>
        <?php } ?>
    <?php } ?>
</table>

Answer 5

have you tried a foreach with a key/value pair? can you show us your for loops currently? a print_r/var_dump for the resulting array will make it easier for someone to help you.

foreach ($result as $key=>$value) {
  print "Name Row\n";
  for (each display row) {

That or as Ascherer suggests make a new multidimensional array that will make nested for loops unnecessary.