如何利用PHP开发自动化商品库存管理工具

<?php
$host = "localhost";
$dbname = "inventory_management";
$username = "root";
$password = "";

$pdo = new PDO("mysql:host=$host;dbname=$dbname;charset=utf8", $username, $password);
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$pdo->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);

<?php
// 添加商品
function addProduct($name, $price, $quantity) {
    global $pdo;
    
    $stmt = $pdo->prepare("INSERT INTO products (name, price, quantity) VALUES (?, ?, ?)");
    $stmt->execute([$name, $price, $quantity]);
    
    return $pdo->lastInsertId();
}

// 修改商品信息
function updateProduct($id, $name, $price, $quantity) {
    global $pdo;
    
    $stmt = $pdo->prepare("UPDATE products SET name = ?, price = ?, quantity = ? WHERE id = ?");
    $stmt->execute([$name, $price, $quantity, $id]);
    
    return $stmt->rowCount();
}

// 删除商品
function deleteProduct($id) {
    global $pdo;
    
    $stmt = $pdo->prepare("DELETE FROM products WHERE id = ?");
    $stmt->execute([$id]);
    
    return $stmt->rowCount();
}

<?php
// 更新库存数量
function updateQuantity($id, $quantity) {
    global $pdo;
    
    $stmt = $pdo->prepare("UPDATE products SET quantity = ? WHERE id = ?");
    $stmt->execute([$quantity, $id]);
    
    return $stmt->rowCount();
}

<?php
// 添加销售记录
function addSale($productId, $quantity, $saleDate) {
    global $pdo;
    
    $stmt = $pdo->prepare("INSERT INTO sales (product_id, quantity, sale_date) VALUES (?, ?, ?)");
    $stmt->execute([$productId, $quantity, $saleDate]);
    
    return $pdo->lastInsertId();
}