how to print data retrieved from database using db_query

I tried using the db_fetch_object in Drupal 7 and it is not working.

In my case all I want to achieve the following:

1. Identify select the last book that was created by the user who is logged in.
2. Select the last node that was created by the user who is logged in.


Right now I am just attempting to access the node and book table in the database. I attempted to use the code produced by siliconmeadow... noted below :

$result = db_query('SELECT name FROM {users} WHERE uid = %d', 2);
while ( $obj = db_fetch_object ($result) ) {
  print $obj->name;
}

My version looks like this:

function select_last_node_created() { 
 $result = db_query('SELECT nid, title FROM {node}');
 while ( $obj = db_fetch_object ($results)){
   print $obj->nid;  
   print $obj->title;
   }

I have a number of questions.

1. Is there a definition of the arguments for db_query? I do not understand the arguments "Select nid" or "title FROM {node}"..... I saw these terms in the database API.
http://drupal.org/node/310072
I do not know how to manipulate the arguments to meet my individual needs. The database API does not explain it well enough for me... I am rather new to PHP coding and the Drupal nomenclature.

2. When I attempt to run the above code I get an error message:

Fatal error: Call to undefined function db_fetch_object() in ....sites\all\modules\my_rules\add_child.rules.inc on line 57

3. How do I select the last book created by the current user from the {book} table of the database?
4. How do I update the {BID} of the last node created by the current user ?...Which table would I modify and how?.... I want to make the last node created by the current user a child of the last book created by the current user.


By the way.... I am creating this as a rules 2 enabled module.

Thanks,

Spineless

i am new to drupal and php
I copied the same code and pasted i.e

$result = db_query('SELECT * FROM {users} WHERE uid = %d', 2);
while ( $obj = db_fetch_object ($result) ) {
  print $obj->name;
}

but i am getting a unique error
Recoverable fatal error: Argument 2 passed to db_query() must be an array, integer given,
please help.

Wow. Wherever that bad code came from, never go there again.

For starters, don't use database functions when you don't need to. Drupal already defines a very complete API for dealing with nodes. Use that.

Code that replicates what you mentioned would be:

  // Load *all* nodes
  $nodes = node_load_multiple(FALSE);
  foreach ($nodes as $nid => $node) {
    print $nid;
    print $node->title;
  }
}

If you want the very latest node created, don't use SQL to find it. Use an EntityFieldQuery instead. Here's one way. (There's probably a way to take the MAX creation date, but that's your research project.)

function select_last_node_created() {
  $efq = new EntityFieldQuery();
  // Get a list of nodes in descending  creation date order.
  $result = $query
    ->entityCondition('entity_type', 'node')
    ->propertyOrderBy('created', 'DESC')
    ->execute();
  if (empty($result['node'])) {
    return NULL;
  }
  $nids = array_keys($result['node']);
  // Get the ID of the first (newest) node.
  $nid = reset($nids);
  // Return fully populated node.
  $node = node_load($nid);
  return $node;
}

I'm afraid that I don't know about the book module or database structure. You'll want to find out if books are entities and whether they have an API defined.

If you run into a situation where you simply have to use DB queries to get the job done, have a good long read of http://drupal.org/developing/api/database, first. That will answer your questions. Once you do, you'll see:

Don't use db_query(). use db_select(), instead.

Also, don't use db_fetch_object() (whatever that is). Use $result->fetch() or result->fetchAll() instead. See http://drupal.org/node/1251174 for a list of ways to get data back from your query.

Then you want something like this:

$result = db_select('college', 'm')
      ->fields('m')
      ->execute();

foreach ($result as $r) {
  print $r->college_id;
  print $r->student_name;
  print $r->emailid;
}