PHP somo la 97: Jinsi ya kuchakata data zaidi kwa kutumia ORM

Katika somo hili utakwenda kujifunz akuchakata data zaidi kw akutumia ORM kama ku join table

Hapa ni hatua za kuunda somo linalofuata kwa ajili ya kuongeza jedwali la transactions pamoja na faili la transactions.php ili kuonyesha orodha ya wateja na bidhaa walizonunua pamoja na bei zao.

Hatua 1: Kuingiza Jedwali la transactions kwenye Hifadhidata

Kwanza, tutahitaji kuunda jedwali jipya la transactions kwenye hifadhidata yako. Jedwali hili litakuwa na uhusiano (foreign keys) kwa jedwali la customers na products ili kurekodi bidhaa na wateja wanaohusiana.

CREATE TABLE transactions (
    id INT AUTO_INCREMENT PRIMARY KEY,
    customer INT NOT NULL,
    product INT NOT NULL,
    created TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (customer) REFERENCES customers(id),
    FOREIGN KEY (product) REFERENCES products(id)
);

Maelezo ya Fields:

id: ID ya kila transaction (inajijenga kiotomatiki).
customer: Hii ni customer_id kutoka kwenye jedwali la customers.
product: Hii ni product_id kutoka kwenye jedwali la products.
created: Hii inarekodi wakati wa kutokea kwa transaction (inaonekana kiotomatiki kama CURRENT_TIMESTAMP).

Hatua 2: Kuunda Faili la transactions.php

Sasa tutaunda faili la transactions.php ambalo litachukua taarifa za wateja na bidhaa walizonunua pamoja na bei zao. Kwenye faili hili, tutachukua taarifa kutoka kwenye jedwali la transactions na kuonyesha orodha ya wateja na bidhaa walizonunua.

<?php
require_once 'dbclass.php';
require_once "model.php";

// Anza ORM kwa ajili ya transactions
$transactionORM = new Model('transactions');
$productORM = new Model('products');
$customerORM = new Model('customers');
$error = "";

// Pata transactions zote
$transactions = $transactionORM->all();

?>

<!DOCTYPE html>
<html lang="sw">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Orodha ya Miamala</title>
</head>
<body>

<h2>Orodha ya Miamala</h2>
<?php if (!empty($transactions)): ?>
    <table border="1">
        <tr>
            <th>ID ya Transaction</th>
            <th>Jina la Mteja</th>
            <th>Jina la Bidhaa</th>
            <th>Bei</th>
            <th>Tarehe</th>
        </tr>
        <?php foreach ($transactions as $transaction): ?>
            <?php
                // Pata mteja na bidhaa kwa kutumia IDs
                $customer = $customerORM->find($transaction['customer']);
                $product = $productORM->find($transaction['product']);
            ?>
            <tr>
                <td><?= htmlspecialchars($transaction['id']); ?></td>
                <td><?= htmlspecialchars($customer['name']); ?></td>
                <td><?= htmlspecialchars($product['name']); ?></td>
                <td><?= htmlspecialchars($product['price']); ?></td>
                <td><?= htmlspecialchars($transaction['created']); ?></td>
            </tr>
        <?php endforeach; ?>
    </table>
<?php else: ?>
    <p>Hakuna miamala iliyorekodiwa.</p>
<?php endif; ?>

</body>
</html>

Maelezo ya Code:

ORM kwa Transactions, Customers, na Products: Tumetumia ORM kwa transactions, customers, na products ili tupate taarifa za wateja na bidhaa zinazohusiana na transaction.
Pata Miamala: Tunachukua taarifa zote za miamala kutoka kwenye jedwali la transactions kwa kutumia $transactionORM->all().
Pata Mteja na Bidhaa kwa ID: Kwa kila transaction, tunatumia IDs za mteja na bidhaa ili kupata majina yao kutoka kwenye jedwali la customers na products.
Onyesha Orodha ya Miamala: Tunatengeneza meza ili kuonyesha ID ya Transaction, Jina la Mteja, Jina la Bidhaa, Bei ya Bidhaa, na Tarehe ya Transaction.
Ujumbe wa Makosa: Ikiwa hakuna miamala iliyorekodiwa, itaonyesha ujumbe wa "Hakuna miamala iliyorekodiwa."

Hatua 3: Kuhakikisha Uhusiano Kati ya Jedwali la transactions, products, na customers

Hakikisha kuwa unatumia foreign keys ili kuunganisha jedwali la transactions na ya products na customers kwa kutumia IDs. Hii itahakikisha kuwa data ya miamala ni sahihi na ina uhusiano na bidhaa na wateja waliopo kwenye hifadhidata yako.

Hatua 4: Kuongeza Miamala

Katika sehemu ya kuongeza miamala, tunaweza kutoa fomu ya kuongeza miamala, ambapo mteja atachagua bidhaa na itarekodiwa kwenye jedwali la transactions.

<?php
// Kushughulikia fomu ya kuongeza transaction
if ($_SERVER["REQUEST_METHOD"] === "POST" && isset($_POST['action']) && $_POST['action'] === 'create') {
    $customer_id = $_POST['customer_id'];
    $product_id = $_POST['product_id'];

    if (!empty($customer_id) && !empty($product_id)) {
        $data = [
            'customer' => $customer_id,
            'product' => $product_id
        ];

        if ($transactionORM->create($data)) {
            header("Location: transactions.php");
            exit();
        } else {
            $error = "Imeshindikana kuongeza transaction.";
        }
    } else {
        $error = "Tafadhali chagua mteja na bidhaa.";
    }
}
?>

<form action="" method="post">
    <input type="hidden" name="action" value="create">
    <label for="customer_id">Chagua Mteja:</label>
    <select name="customer_id" required>
        <?php
        $customers = $customerORM->all();
        foreach ($customers as $customer) {
     ...

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