db_affected_rows gives fatal error in drupal 7

Question

How can i get the number of affected rows in drupal 7? db_affected_rows which i was used in d6 is not working in d7. It shows an error

 $bool = db_query("SELECT * FROM {template_config} WHERE user_role = ':d'",array(':d'=> $id));
        $num = db_affected_rows();
        if ($num != 0) {
            $result = db_fetch_array($bool);
            $custom_theme = $result['theme_name'];
        }

i want to check if there is any affected rows.db_num_rows also is not working in d7
How can i do this in d7?

Answer 1

There is no db_affected_rows() in Drupal 7 I'm afraid. Also you don't need include the quotes in your variable placeholder. Your code might look a little more like this:

$results = db_query("SELECT * FROM {template_config} WHERE user_role = :role", array(':role' => 'the_role'))->fetchAll();

if (count($results) > 0) {
  $first_result = $results[0];

  $custom_theme = $first_result->theme_name;
}

It could be even simpler though:

if ($result = db_query("SELECT * FROM {template_config} WHERE user_role = :role", array(':role' => 'the_role'))->fetchObject()) {
  $custom_theme = $result->theme_name;
}

Answer 2

Drupal 7 is based on PDO as database abstraction layer. That's why a lot of functions have changed compared to D6. To get the number of affected rows, you can use the rowCount method.

By the way, in Drupal 7 you can simply foreach() over a database query result. When using foreach, you don't even need to check if the result has more than 0 rows. See db_query documentation for more info. The following example comes from that page:

<?php
$uid = 1;
$result = db_query('SELECT n.nid, n.title, n.created FROM {node} n WHERE n.uid = :uid', array(':uid' => $uid));
// Result is returned as a iterable object that returns a stdClass object on each iteration
foreach ($result as $record) {
  // Perform operations on $record->title, etc. here.
  // in this example the available data would be mapped to object properties:
  // $record->nid, $record->title, $record->created
}
?>

Answer 3

$bool = db_query("SELECT * FROM {template_config} WHERE user_role = ':d'",array(':d'=> $id));
        $num = db_affected_rows($bool);

OR

$num = db_num_rows($bool);

    if ($num != 0) {
        $result = db_fetch_array($bool);
        $custom_theme = $result['theme_name'];
    }

Try this you have forgot passing the argument.

Answer 4

In drupal 7 use $pdos->rowCount(); to get the affected rows count.

$result = db_query('<your query>');
$affected_rows = $result->rowCount();