如何在 pdo 中返回 max(id)

Question

I am trying to return the last id and increment it to put in the value attribute. I can make it work with old mysql but not with the PDO. I am learning (I think) PDO but it is not making sense.

Below is the code.

 <td><label for="invNum"></label>Invoice</td> <?php $stmt = $dbconn->prepare("SELECT max(invId) FROM invoices"); $stmt->execute(); $invNum = $stmt->fetch(); /* mysql_select_db("customers", $dbconn); $result = mysql_query("SELECT max(invId) FROM invoices"); if (!$result) { die('Could not query:' . mysql_error()); } $invNum = mysql_result($result, 0);*/ ?> <td><input type="text" name="invNum" id="invNum" size="12" value="<?php echo ++$invNum; ?>" /></td>

Answer 1

Try this :

  $stmt = $dbconn->prepare("SELECT MAX(invId) AS max_id FROM invoices");
  $stmt -> execute();
  $invNum = $stmt -> fetch(PDO::FETCH_ASSOC);
  $max_id = $invNum['max_id'];

Answer 2

If you want to enter a new line right away:

$pdo = new PDO('mysql:host=localhost;dbname=databasename','username','password');

$statement = $pdo->prepare("INSERT INTO invoices(data1, data2, data3) VALUES (?, ?, ?)");
$statement->execute(array('bla', 'bla', 'bla'));   

$newID = $pdo->lastInsertId();