Question

It seems to me that both rowCount() and exec() Returns the number of rows affected by the last SQL statement .

Why keep the duplicate stuff there?

Answer 1

They are not duplicate they have different-2 roles to play at different situations.

exec() => Execute the sql and returns
affected rows.

rowCount() => Does not executed any
statement but returns rows affected by
last sql.

They are different in this way

If you are using execute() then rowCount come into it’s role

$del = $dbh->prepare('DELETE FROM fruit');
$del->execute();
$count = $del->rowCount();

And when you are using exec no need to rowCount()

$count = $dbh->exec("DELETE FROM fruit WHERE colour = 'red'");
print("Deleted $count rows.\n");