PHP如何在包装器中调用数据库时获取最后一个插入ID

Question

<?php
$sql = "insert into user (firstname, lastname) values (:firstname, :lastname)";
$arg = array("John", "Doe");
$stmt = pdo($sql, $arg);

$id = $pdo->lastInsertId();
print $id;


function pdo($sql, $args = NULL){

  $dsn = "mysql:host=localhost;dbname=db;charset=utf8mb4";

  try {
    $pdo = new \PDO($dsn, "user", "123");
  } catch (\PDOException $e) {
    throw new \PDOException($e->getMessage(), (int)$e->getCode());
  }

  if (!$args){
    return $pdo->query($sql);
  }

  $stmt = $pdo->prepare($sql);
  $stmt->execute($args);

  return $stmt;

}

?>

I use a wrapper to call database queries, this has always worked well.

Except for today when I need to get the last insert ID. The error is "Undefined variable pdo"

I see why there is an error message, but not sure what is the solution while at the same time keeping the wrapper function?

Answer 1

You might just want to have a function create the DB connection and let the application code use the PDO API directly. That would be simpler than trying to wrap all the functionality of the PDO API. It would get complicated to do that.

If you really need a wrapper around your PDO connection, then you may want to create a class with different methods operating on the same connection. The class could have a special insert method that returns the inserted ID as well as a fetch method to retrieve results.