为什么这些参数在这个Mysql查询中没有经过？

Question

What is wrong with this query?

I can't get this query to pass these arguments!

$offset = 5;
$rowsperpage = 10;
$stmt = $db->prepare("SELECT * FROM table ORDER BY ID DESC LIMIT ?,?");
if ($stmt->execute(array($offset, $rowsperpage))) {
  while ($row = $stmt->fetch()) {
    echo $row['title'];
  }
}

If I change the query to this it works fine, but I need to pass the strings because they are dynamic.

$stmt = $db->prepare("SELECT * FROM table ORDER BY ID DESC LIMIT 5,10");
if ($stmt->execute(array($offset, $rowsperpage))) {
  while ($row = $stmt->fetch()) {
    echo $row['title'];
  }
}

Answer 1

I have a feeling that "lazy execution" treats all parameters as strings and thus enclose them in quotes.

So, either bind your parameters explicitly, using bind_param instead of passing array into execute()

or set emulation mode to off

$db->setAttribute( PDO::ATTR_EMULATE_PREPARES, false );

right after connect.

anyway, you have to get in touch with the error message first.
So, setting this one

$db->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );

will reveal the error message to you

Answer 2

你忘了做bind_param来填补空白