How do I update the body of a node using a query? Let us consider I have a node called "DrupalTest" for which I need to update the body content using AJAX.

Shall I execute a query, or is there any other way to update the body content?
Load the node using node_load().
Set the body property of the node; examine the node object to determine which one the body property is. If you have the Devel module installed, kpr() will help you there.
Save the node using node_save().


This ensures that the hooks associated with updating a node get executed, and that the cache is properly cleared.