PHP Script to output JSON object for nestable jquery plugin

I need a php script that takes the attached MySQL output and echos a JSON response in this format - [{"id":1},{"id":2,"children":[{"id":3},{"id":4},{"id":5,"children":[{"id":6},{"id":7},{"id":8}]},{"id":9},{"id":10}]},{"id":11},{"id":12}]. The actual tree needs to be UPC and Description -Distributor --Warehouse and Division or DCCode I assume it is a nested loop based on change in values