0

I try to create a condition that checks if user has already created a node.

I use this code which returns the last created node by the user. Adding simple if statement I can return true/false.

$xxx = db_query("SELECT nid FROM {node} WHERE (type = :type1) AND (uid = '123')", array("type1" => 'nodetype_x'))->fetchField();
return $xxx;

I tried to do it more efficient to check only for first result like this.

$xxx = db_query("
IF EXISTS(
      SELECT nid FROM {node} WHERE (type = :type1) AND (uid = '123')
)
SELECT 1
ELSE
SELECT 0", array("type1" => 'nodetype_x'))->fetchField();

But get syntax error. What would be the correct syntax? Thank you

0

There is no need to use IF EXISTS() with db_query(). Drupal core code never use it.

// comment_num_new()
return db_query('SELECT COUNT(cid) FROM {comment} WHERE nid = :nid AND created > :timestamp AND status = :status', array(
  ':nid' => $nid,
  ':timestamp' => $timestamp,
  ':status' => COMMENT_PUBLISHED,
))->fetchField();
  // aggregrator_cron()
  $result = db_query('SELECT * FROM {aggregator_feed} WHERE queued = 0 AND checked + refresh < :time AND refresh <> :never', array(
    ':time' => REQUEST_TIME,
    ':never' => AGGREGATOR_CLEAR_NEVER,
  ));
  $queue = DrupalQueue::get('aggregator_feeds');
  foreach ($result as $feed) {
    if ($queue->createItem($feed)) {
      // Add timestamp to avoid queueing item more than once.
      db_update('aggregator_feed')->fields(array('queued' => REQUEST_TIME))->condition('fid', $feed->fid)->execute();
    }
  }
  // aggregrator_feed_load()
  $feeds = &drupal_static(__FUNCTION__);
  if (!isset($feeds[$fid])) {
    $feeds[$fid] = db_query('SELECT * FROM {aggregator_feed} WHERE fid = :fid', array(':fid' => $fid))->fetchObject();
  }

  return $feeds[$fid];

// aggregrator_expire()
$iids = db_query('SELECT iid FROM {aggregator_item} WHERE fid = :fid AND timestamp < :timestamp', array(
  ':fid' => $feed->fid,
  ':timestamp' => $age,
))->fetchCol();
if ($iids) {
  db_delete('aggregator_category_item')->condition('iid', $iids, 'IN')->execute();
  db_delete('aggregator_item')->condition('iid', $iids, 'IN')->execute();
}

In your case, the following code is enough.

if ($nid = db_query("SELECT nid FROM {node} WHERE type = :type1 AND uid = '123'", array("type1" => 'nodetype_x'))->fetchField()) {
  // There is such a node.
}
else {
  // There isn't such a node.
}
  • HI, so does this code runs through all results and gives me only one or the code returns right after it finds first one? My aim was to do it more performant. Thank you. – loparr May 12 '15 at 9:39
  • Leave this kind of optimisations to Drupal database drivers. There are other optimisations you can use; for example caching what obtained from a query. – kiamlaluno May 12 '15 at 12:35
0

This is really not the ideal way to do this. Instead you may want to try something like:

$query = db_select('node', 'n')
  ->condition('n.type', $type)
  ->condition('n.uid', $uid)
  ->fields('n', array('nid'));

$count = $query->countQuery()->execute()->fetchField();

if ($count) {
  return true;
}

return false;
  • is this query going to stop after it finds first result? It seems to me that it does the same but with different code. – loparr May 11 '15 at 20:47
  • Drupal doesn't use code similar to this. It just uses the result of fetchField() as boolean value. – kiamlaluno May 12 '15 at 5:56
  • No, it isn't going to stop on the first result. It converts the query to a countQuery(). Any count other than 0 will return TRUE. – RoloDMonkey May 12 '15 at 11:52

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