Remove repeating data in a column

问题

I am currently developing an ordering system where a customer can order many items. I also have an admin where he/she can see all the orders on that day. The Admin can view the name of the customer, the total payable, the products and the quantity of the product the customer have ordered.

I am currently seeing this results using my query.

 Name   | Payable | Product   | Quantity
 Test   |   165   | keychain  | 3
 Test   |   165   | Tumbler   | 1
 Miguel |   525   | Keychain  | 3
 Miguel |   525   | Magic Mug | 3
 Dandel |   1010  | keychain  | 3
 Dandel |   1010  | T-shirt   | 2
 Dandel |   1010  | Keychain  | 3
 Dandel |   1010  | Mug       | 5

This is my query.

 $result = mysql_query("
        SELECT reservation.firstname, reservation.lastname, reservation.payable, reservation.city, orders.product, orders.qty, reservation.date
        FROM orders
        INNER JOIN reservation
        ON orders.confirmation = reservation.confirmation 
        WHERE reservation.date = CURDATE() && reservation.city = '24th Floor'
        ");
    while($row = mysql_fetch_array($result))
        {
            echo '<tr>';
            echo '<td style="border: 1px solid black;">'.$row['firstname'].'</td>';
            echo '<td>'.$row['payable'].'</td>';
            echo '<td>'.$row['product'].'</td>';
            echo '<td>'.$row['qty'].'</td>';
            echo '</tr>';
        }

I want to get results like this. How can I do it?

 Name   | Payable | Product   | Quantity
 Test   |   165   | keychain  | 3
        |         | Tumbler   | 1
 Miguel |   525   | Keychain  | 3
        |         | Magic Mug | 3
 Dandel |   1010  | keychain  | 3
        |         | T-shirt   | 2
        |         | Keychain  | 3
        |         | Mug       | 5

回答1:

You can maintain some state while iterating which keeps track of whether the current row is a new name/payable:

$last_name_seen = NULL;

while ($row = mysql_fetch_array($result)) {
    $firstname = "";
    $payable = "";
    if ($last_name_seen === NULL || $row['firstname'] != $last_name_seen) {
        $last_name_seen = $row['firstname'];
        $firstname = $row['firstname'];
        $payable = $row['payable'];
    }
    echo '<tr>';
    echo '<td style="border: 1px solid black;">'.$firstname.'</td>';
    echo '<td>'.$payable.'</td>';
    echo '<td>'.$row['product'].'</td>';
    echo '<td>'.$row['qty'].'</td>';
    echo '</tr>';
}

Note that your MySQL query should have some ORDER BY clause, to generate the ordering you want, e.g.

ORDER BY Name, Product;

As the comments above also suggest, if you are using a deprecated PHP API, you should consider upgrading to something more modern. But, the logic used in the above loop would not change much with changing the MySQL API.

回答2:

You have to set flag for name & payable column & use array_column(),array_unique() to get unique column values :

<?php

$result = array(array("Name"=>"Test","Payable"=>'165',"Product"=>"keychain","Quantity"=>3),array("Name"=>"Test","Payable"=>'165',"Product"=>"Tumbler","Quantity"=>1));

$name_arr = array_unique(array_column($result, 'Name'));
$payable_arr = array_unique(array_column($result, 'Payable'));

$name_flag = 0;
$pay_flag = 0;

echo "<table border='1'>";

for($i=0;$i<count($name_arr);$i++)
{

    for($j=0;$j<count($payable_arr);$j++)
    {
        foreach($result as $list)
        {
            if($list['Name'] == $name_arr[$i] && $list['Payable'] == $payable_arr[$j])
            {
                if($name_flag==0 && $pay_flag==0)
                {
                    echo "<tr>";
                    echo "<td>".$name_arr[$i]."</td>";
                    echo "<td>".$payable_arr[$j]."</td>";
                    echo "<td>".$list['Product']."</td>";
                    echo "<td>".$list['Quantity']."</td>";
                    echo "</tr>";
                }
                else
                {
                    echo "<tr>";
                    echo "<td>&nbsp;</td>";
                    echo "<td>&nbsp;</td>";
                    echo "<td>".$list['Product']."</td>";
                    echo "<td>".$list['Quantity']."</td>";
                    echo "<tr>";
                }
                $name_flag++;
                $pay_flag++;
            }
        }
    }
    $name_flag=0;
    $pay_flag=0;
}
echo "</table>";
?>

来源：https://stackoverflow.com/questions/52639451/remove-repeating-data-in-a-column

标签

php

mysql

concatenation

distinct