MongoDB update complex document - mongodb

Question

I search for some similar example, but didn't find something good.
{
"_id" : ObjectId("571dea148234534308a290e"),
"user" : "myusername",
"duration" : "",
"test_details" : [
{
"test" : "New",
"test_id" : "0",
"comments" : "will be some text",
"text" : ""
},
{
"test" : "**to change value here**",
"test_id" : "1",
"comments" : "will be some text",
"text" : "**to change value here**"
},
{
"test" : "New",
"test_id" : "2",
"comments" : "will be some text",
"text" : ""
},
{
"test" : "New",
"test_id" : "3",
"comments" : "will be some text",
"text" : ""
"sub_test_details" : [
{
"56eed334534566ac5668ca18" : [
{
"sub_test" : "New",
"sub_test_id" : "0",
"sub_comments" : "will be some text",
"sub_text" : ""
},
{
"sub_test" : "New",
"sub_test_id" : "1",
"sub_comments" : "will be some text",
"sub_text" : ""
},
{
"sub_test" : "New",
"sub_test_id" : "2",
"sub_comments" : "will be some text",
"sub_text" : ""
}
]
},
{
"56eed3b1f37d66ac5668ca19" : [
{
"sub_test" : "New",
"sub_test_id" : "0",
"sub_comments" : "will be some text",
"sub_text" : ""
},
{
"sub_test" : "New",
"sub_test_id" : "1",
"sub_comments" : "will be some text",
"sub_text" : ""
},
{
"sub_test" : "**to change value here**",
"sub_test_id" : "2",
"sub_comments" : "will be some text",
"sub_text" : "**to change value here**"
}
]
}
]
},
{
"test" : "New",
"test_id" : "4",
"comments" : "will be some text",
"text" : ""
}
],
}
And the questions are:
What is query to update text="Completed Successfully" and test="Done" where _id" : ObjectId("571dea148234534308a290e").test_id=1.
What is query to update sub_text="Sub Completed Successfully" and sub_test="Sub Done" where _id" : ObjectId("571dea148234534308a290e").test_details.test_id=3.sub_test_details.56eed3b1f37d66ac5668ca19.sub_step_id=2
In my case i will get id, test_id, exam_num(56eed3b1f37d66ac5668ca19), sub_test_id will be parameters to find relevant place for updating.
An array elements size not always constant. Therefore I use id to specify exactly which element I am looking for.
Thanks

Answer 1

MongoDB allows using indexes while updating nested documents, so the query for your first question should be most likely this:
db.test.update({"_id": ObjectId("571dea148234534308a290e"), "test_details.test_id": "1"}, {"$set": {"test_details.$.test": "Done", "test_details.$.text": "Completed Succesfully"}})
Unfortunately this works only on first level of embedding, so you can't use more than one positional operator $. There are two ways to change embedded data in this case: first, you should know index of the document you want to update, and the second requires some data structure changes. Instead of using lists to hold nested documents in your test_details you should use dictionary, in this way:
{
"test" : "New",
"test_id" : "3",
"text" : ""
"sub_test_details" : {
"56eed334534566ac5668ca18" : {
"0": {
"sub_test" : "New",
"sub_text" : ""
},
"1": {
"sub_test" : "New",
"sub_text" : ""
},
"2": {
"sub_test" : "New",
"sub_text" : ""
}
},
"56eed3b1f37d66ac5668ca19" : {
"0": {
"sub_test" : "New",
"sub_text" : ""
},
"1": {
"sub_test" : "New",
"sub_text" : ""
},
"2": {
"sub_test" : "**to change value here**",
"sub_text" : "**to change value here**"
}
}
}
}
and the query will be like this:
db.test.update({"_id": ObjectId("571e32c0907445669f11037e"), "test_details.test_id": "3"}, {"$set": {"test_details.$.sub_test_details.56eed334534566ac5668ca18.0.sub_test": "Done", "test_details.$.sub_test_details.56eed334534566ac5668ca18.0.sub_text": "Completed Succesfully"}})
Also see this question where similar problems are discussed

Answer 2

The update method should do that for you, you should use $addToSet, to ensure no duplicates go into an array given the id, and upsert:true to update existing docs with the same id. The below should work
db.tests.update(
{_id" : ObjectId("571dea148234534308a290e"},
{$addToSet:
{ test_details:
{test_id: "0",
test: "Done",
text: "Completed Successfully"
}}},
{upsert: true}
);