PDO相当于mysql_num_rows或mssql_num_rows

Question

I know this question has been asked before but it seems like the solutions have been specific to the problem presented.

I have a codebase with hundreds of instances where mssql_num_rows is used.

Code example:

$db->execute($sql);

if ($db->getRowsAffected() > 0) {
    $total = $db->fetch();

In db class:

$this->rowsaffected = mssql_num_rows($this->query_result);

• I can't create generic SELECT count(*) FROM table queries as I have too many specific select statements.
• I could run a preg_replace to remove everything between SELECT and FROM and then replace with a COUNT(*) and run a second query but this assumes all queries are setup a certain way.
• I could fetchAll first then count() the results but that means upgrading all instances of the if statements.

So what is the best all around replacement to a *_num_rows function if people are updating their code to PDO. Not something that solves a specific problem, but something that replaces the functionality of *_num_rows. If that's not possible what allowed it to be possible before?

Answer 1

If you want to count the rows you can do this with PDO:

$sql = 'select * from users';
$data = $conn->query($sql);
$rows = $data->fetchAll();
$num_rows = count($rows);

There is no way to directly count rows when using a SELECT statement with PDO.