使用PHP开发的费用报销模块在企业资源计划（ERP）系统中的应用

CREATE TABLE expenses (
  id INT PRIMARY KEY AUTO_INCREMENT,
  employee_id INT,
  expense_type VARCHAR(50),
  amount DECIMAL(10,2),
  reason VARCHAR(255),
  status VARCHAR(20),
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
);

class Expense
{
  private $conn;

  public function __construct($db)
  {
    $this->conn = $db;
  }

  // 提交费用申请
  public function create($employee_id, $expense_type, $amount, $reason)
  {
    $query = "INSERT INTO expenses (employee_id, expense_type, amount, reason, status) 
              VALUES (:employee_id, :expense_type, :amount, :reason, 'pending')";
    
    $stmt = $this->conn->prepare($query);
    $stmt->bindParam(':employee_id', $employee_id);
    $stmt->bindParam(':expense_type', $expense_type);
    $stmt->bindParam(':amount', $amount);
    $stmt->bindParam(':reason', $reason);
    
    if ($stmt->execute()) {
      return true;
    } else {
      return false;
    }
  }

  // 审批费用申请
  public function approve($expense_id)
  {
    $query = "UPDATE expenses SET status = 'approved' WHERE id = :expense_id";
    
    $stmt = $this->conn->prepare($query);
    $stmt->bindParam(':expense_id', $expense_id);
    
    if ($stmt->execute()) {
      return true;
    } else {
      return false;
    }
  }

  // 支付费用
  public function pay($expense_id)
  {
    $query = "UPDATE expenses SET status = 'paid' WHERE id = :expense_id";
    
    $stmt = $this->conn->prepare($query);
    $stmt->bindParam(':expense_id', $expense_id);
    
    if ($stmt->execute()) {
      return true;
    } else {
      return false;
    }
  }
}

// 创建费用报销实例
$expense = new Expense($db);

// 创建费用申请
$expense->create($employee_id, $expense_type, $amount, $reason);

// 审批费用申请
$expense->approve($expense_id);

// 支付费用
$expense->pay($expense_id);