How to Update Parts of a document in Couchbase

In scanning the docs I cannot find how to update part of a document.

for example - say the whole document looks like this:

{
      "Active": true,
      "Barcode": "123456789",
      "BrandID": "9f3751ef-f14f-464a-bb86-854e99cf14c0",
      "BuyCurrencyOverride": ".37",
      "BuyDiscountAmount": "45.00",
      "ID": "003565a3-4a0d-47d9-befb-0ac642cb8057",
}

but I only want to work with part of the document as I don't want to be selecting / updating the whole document in many cases:

{
      "Active": false,
      "Barcode": "999999999",
      "BrandID": "9f3751ef-f14f-464a-bb86-854e99cf14c0",
      "ID": "003565a3-4a0d-47d9-befb-0ac642cb8057",
}

How can I use N1QL to just update those fields? Upsert completely replaces the whole document and update statement is not that clear.

Thanks

Solution

The answer to your question depends on why you want to update only part of the document (e.g., are you concerned about network bandwidth?), and how you want to perform the update (e.g., from the web console? from a program using the SDK?).

The 4.5 sub-document API, for which you provided a link in your comment, is a feature only available via the SDK (e.g., from Go or Java programs), and the goal of that feature is to reduce network bandwidth by no transmitting entire documents around. Does your use case include programmatic document modifications via the SDK? If so, then the sub-document API is a good way to go.

Using the "UPDATE" statement in N1QL is a good way to change any number of documents that match a pattern for which you can specify a "WHERE" clause. As noted above, it works very similarly to the "UPDATE" statement in SQL. To use your example above, you could change the "Active" field to false in any documents where the BuyDiscountAmount was "45.00":

UPDATE my bucket SET Active = false WHERE BuyDiscountAmount = "45.00"

When running N1QL UPDATE queries, almost all the network traffic will be between the Query, Index, and Data nodes of your cluster, so a N1QL update does not cause much network traffic into/out-of your cluster.

If you provide more details about your use case, and why you want to update only part of your documents, I could provide more specific advice on the right approach to take.