How can I rename field of document with N1QL?

SQL++
8

I know it’s been a while, instead of using SQL++ (N1QL) there is another option.

If you have performance issues or need to process a very large data set the Eventing service works great for renaming both top-level-fields or subfields.

Below I show a “point tool” written to take care of the original rename request.

function OnUpdate(doc, meta) {
    // test if old field exists
    if (doc.id) {
        // modify the local copy of the JSON doc sourced via the DCP stream
        doc.carId = doc.id;
        delete doc.id;
        // update the entire document via a bucket binding to the source in read/write mode.
        binding_to_source[meta.id] = doc;
    }
}

The above function needs to listen to your source bucket (or keyspace if 7.0+) and have a bucket binding alias of binding_to_source to your source bucket (or keyspace if 7.0+) in mode read+write.

For performance you can also increase the # workers in your Eventing function to the number of vCPUs on your Eventing node. I did millions of documents quite fast using this technique.

For more details on using Eventing refer to Examples: Using the Eventing Service | Couchbase Docs

Best

Jon Strabala
Principal Product Manager - Server‌