Query from multiple MySQL tables using PHP

Question

I have the following function which pulls in invoice data from tables invoices, however how can I get data from the customers table matching up invoice number:

So I guess need to get * from customers tables where invoice = invoice ?

PHP

// the query
    $query = "SELECT * FROM invoices ORDER BY invoice ASC";

    // mysqli select query
    $results = $mysqli->query($query);

    // mysqli select query
    if($results) {

        print '<table class="table table-striped table-bordered" id="data-table" cellspacing="0"><thead><tr>

                <th><h4>Invoice</h4></th>
                <th><h4>Customer</h4></th>
                <th><h4>Issue Date</h4></th>
                <th><h4>Due Date</h4></th>
                <th><h4>Status</h4></th>
                <th><h4>Action</h4></th>

              </tr></thead><tbody>';

        while($row = $results->fetch_assoc()) {

            print '
                <tr>
                    <td>'.$row["invoice"].'</td>
                    <td>'.$row["customer_name"].'</td>
                    <td>'.$row["invoice_date"].'</td>
                    <td>'.$row["invoice_due_date"].'</td>
                    <td>test</td>
                    <td><a href="invoice-edit.php?id='.$row["invoice"].'" class="btn btn-primary">Edit</a> <a data-invoice-id="'.$row['invoice_id'].'" class="btn btn-danger delete-product">Delete</a></td>
                </tr>
            ';

        }

        print '</tr></tbody></table>';

    } else {

        echo "<p>There are no invoices to display.</p>";

    }

Answer 1

try this..

 $query = "SELECT c.customer_name, i.* FROM invoices as i JOIN customers as c ON i.customer_id = c.id ORDER BY i.invoice ASC";

this will give you customer name as you require.

Refer to http://w3schools.com/sql/sql_join.asp

Answer 2

$query = "SELECT * 
          FROM Invoices I, Customers C 
          WHERE I.invoice = C.invoice
          ORDER BY C.invoice ASC";

If you would prefer a statement without joins..

Answer 3

First of all, it's generally a better idea to include your keys in your select (and it's also easier to troubleshoot) instead of * . However, assuming that these are your fields, you can connect these using a JOIN like so:

SELECT * 
FROM invoices i
JOIN customer c
ON c.invoice = i.invoice
ORDER BY i.invoice

Assuming you have a common key on each table, which as you suggest, is invoice (this is the huge advantage of using a database as opposed to a flat file), you can just join them together (the i and c are just shortcuts which make it easier to read the query).

You can also modify this with a WHERE after the ON row to narrow down your results, such as something like this (assuming you are looking for a specific invoice numbered 12345

SELECT * 
FROM invoices i
JOIN customer c
ON c.invoice = i.invoice
WHERE i.invoice = 12345
ORDER BY i.invoice

SQL is pretty powerful. If you want to read up more, there are some great tutorials here on this site: http://www.w3schools.com/sql/

If you want to call this in your query (using the first example) you can just do it the same way you were, like so:

 while($row = $results->fetch_assoc()) {
        echo $row["invoice"];

}

Edit: In the future it is better to declare your keys in the select. Assuming that customer_name is in the customer table, you would call it as c.customer_name in the select. However, here's how it would work with the wildcard to get everything from both tables. Change your query to this:

SELECT i.*, c.*
FROM invoices i
JOIN customer c
ON c.invoice = i.invoice
ORDER BY i.invoice