mongoDB remove sub-array

Question

Ok is there a quick way to remove the follwoing though PHP mongodb

here is our mongoDB row

{
  "today":""
  "session": "6266262626",
  "products": [
    {
      "barcode": "27788822",
      "item": "village day ticket",
      "price": 1315,
      "qty": "3"
    },
    {
      "barcode": "8544122",
      "item": "village night ticket",
      "price": 1433,
      "qty": "1"
    }
  ]
}

I would like to delete the product

{
      "barcode": "8544122",
      "item": "village night ticket",
      "price": 1433,
      "qty": "1"
}

I know how to update, and insert but cant figure out how to delete it.

Answer 1

here is a mongo command to delete the item, given its barcode :

db.collection.update({session:'6266262626'},{ $pull: { products: { barcode : '8544122' } }})

If you want to delete multiple items from the products array, given an array of barcodes :

db.collection.update({session:'6266262626'},{ $pull: { products: { barcode : {$in : ['27788822','8544122'] } } }})

I don't know the PHP equivalent of those commands, but here is a related question using $pull and PHP which may help :

MongoDB pull array element from a collection

this question is pretty old, but deleting multiple array items in a single query was giving me trouble today, and in my case the above is working out, so maybe it will help somebody else, thanks.

Answer 2

Reading the docs is your friend. Use the positional operator

http://www.mongodb.org/display/DOCS/Updating#Updating-The%24positionaloperator