Respond to creation of a new node.
This hook is invoked from node_save() after the database query that will insert the node into the node table is scheduled for execution, after the type-specific hook_insert() is invoked, and after field_attach_insert() is called.
Note that when this hook is invoked, the changes have not yet been written to the database, because a database transaction is still in progress. The transaction is not finalized until the save operation is entirely completed and node_save() goes out of scope. You should not rely on data in the database at this time as it is not updated yet. You should also note that any write/update database queries executed from this hook are also not committed immediately. Check node_save() and db_transaction() for more info.
$node: The node that is being created.
Note: this list is generated by pattern matching, so it may include some functions that are not actually implementations of this hook.
function hook_node_insert($node) {
db_insert('mytable')
->fields(array(
'nid' => $node->nid,
'extra' => $node->extra,
))
->execute();
}