Respond to updates to a node.
This is a node-type-specific hook, which is invoked only for the node type being affected. See Node API hooks for more information.
Use hook_node_update() to respond to node update of all node types.
This hook is invoked from node_save() after the node is updated in the node table in the database, before field_attach_update() is called, and before hook_node_update() is invoked.
$node: The node that is being updated.
Note: this list is generated by pattern matching, so it may include some functions that are not actually implementations of this hook.
function hook_update($node) {
db_update('mytable')
->fields(array(
'extra' => $node->extra,
))
->condition('nid', $node->nid)
->execute();
}