Question

I have a very basic question on updating a mongo collection.

Suppose I have a mongo document like this:

{"Object_id:.....,"product_id":1234, "color":0}
{"Object_id:.....,"product_id":1234, "color":1} # note the same product_id
{"Object_id:.....,"product_id":12345, "color":0}

Now what i want is:

if product_id == 1234 and color == 1:
# modify that document to color = 2

after update

{"Object_id:.....,"product_id":1234, "color":0}
{"Object_id:.....,"product_id":1234, "color":2} # note the same product_id
{"Object_id:.....,"product_id":12345, "color":0}

Answer 1

To literally do what you want it would be:

db.foo.update({"product_id" : 1234, "color" : 1}, {$set : {"color" : 2}})

If you had multiple occurrences of product_id == 1234 and color == 1 and you wanted to update them all if found, then it is:

db.foo.update({"product_id" : 1234, "color" : 1}, {$set : {"color" : 2}}, false, true)