PHP实现商品库存跟踪与追溯的功能指南

CREATE TABLE products (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(255) NOT NULL,
    quantity INT NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
);

$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "database";

$conn = mysqli_connect($servername, $username, $password, $dbname);

if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}

$name = "iPhone 12";
$quantity = 10;

$sql = "INSERT INTO products (name, quantity) VALUES ('$name', $quantity)";

if (mysqli_query($conn, $sql)) {
    echo "Product added successfully";
} else {
    echo "Error: " . $sql . "<br>" . mysqli_error($conn);
}

$id = 1;
$quantity = 5;

$sql = "UPDATE products SET quantity = $quantity WHERE id = $id";

if (mysqli_query($conn, $sql)) {
    echo "Product quantity updated successfully";
} else {
    echo "Error updating product quantity: " . mysqli_error($conn);
}

$sql = "SELECT * FROM products WHERE id = $id";
$result = mysqli_query($conn, $sql);

if (mysqli_num_rows($result) > 0) {
    $row = mysqli_fetch_assoc($result);
    echo "Product: " . $row["name"] . "<br>";
    echo "Quantity: " . $row["quantity"] . "<br>";
} else {
    echo "Product not found";
}

$id = 1;

$sql = "DELETE FROM products WHERE id = $id";

if (mysqli_query($conn, $sql)) {
    echo "Product deleted successfully";
} else {
    echo "Error deleting product: " . mysqli_error($conn);
}

mysqli_close($conn);