'Update the modified timestamp of this document.'

def touch(self, doctype, docname):

    from frappe.utils import now
    modified = now()
    frappe.db.sql(u'update    `tab{doctype}`    set    `modified`=%s\n DCTB  DCTB  DCTB where    name=%s'.format(doctype=doctype), (modified, docname))
    return modified
