Function: simpleFlatten

Enterprise Edition

Goal: Flatten a document for integration with a non-NOSQL RDBMS.

This function simpleFlatten shows how a document can be flattened into a RDBMS importable record.
Requires Eventing Storage (or metadata collection), a "source" collection, and a "destination" collection.
Will operate on all documents where doc.type === "tosync".
Will write transformed or flattened documents to the destination bucket with the same type and id.
Will also remove the flattened document in the destination bucket when the original source document is removed.
The "destination" collection can be shared (or replicated via XCDR to a business partner) too the cloud (AWS, Azure or GCP).
Note since the document is not available during an OnDelete we will filter by KEY prefix starting with "tosync:".*. This is a hard coded implementation. Refer to genericFlatten for a generic implementation.

simpleFlatten
Input Data/Mutation
Output Data/Mutation

// To run configure the settings for this Function, simpleFlatten, as follows:
//
// Version 7.0+
//   "Listen to Location"
//     bulk.data.source
//   "Eventing Storage"
//     rr100.eventing.metadata
//   Binding(s)
//    1. "binding type", "alias name...", "bucket.scope.collection", "Access"
//       "bucket alias", "dst_col",       "bulk.data.destination",   "read and write"
//
// Version 6.X
//   "Source Bucket"
//     source
//   "MetaData Bucket"
//     metadata
//   Binding(s)
//    1. "binding type", "alias name...", "bucket",     "Access"
//       "bucket alias", "dst_col",      "destination", "read and write"

function OnUpdate(doc, meta) {
    // filter
    if (!doc.type || doc.type !== "tosync") return;

    log("OnUpdate IN  id: "+meta.id+", doc:      ",doc);
    try {
        // convert
        var oracleDoc = {
            // flatten items simple 1:1 map
            "id": doc.id, "type":doc.type,
            // flatten subdoc
            "a_sub_aa": doc.a.aa, "a_sub_ab": doc.a.ab,  "a_sub_ac": doc.a.ac,
            // flatten array
            "b_ary_0": doc.b[0], "b_ary_1": doc.b[1], "b_ary_2": doc.b[2]
        }
        // log
        log("OnUpdate OUT id: "+meta.id+", oracleDoc:",oracleDoc);
    } catch (e) {
        log ("Error on convert: "+e+", id:",meta.id);
    }
    // save
    try {
        dst_col[meta.id] = oracleDoc;
    } catch (e) {
        log("Error on save: "+e+", id:", meta.id);
    }
}

function OnDelete(meta, options) {
    // filter
    if (!(meta.id.startsWith("tosync:"))) return;

    log("OnDelete expired=" + options.expired +" REM id: "+meta.id);
    try {
        delete dst_col[meta.id];
    } catch (e) {
        log("Error on delete: "+e+", id:",meta.id);
    }
}

INPUT: KEY tosync::1

{
  "id": 1,
  "type": "tosync",
  "a": {
    "aa": 1,
    "ab": 2,
    "ac": 3
  },
  "b": [
    1,
    3,
    7
  ]
}

UPDATED/OUTPUT: KEY tosync::1

{
  "id": 1,
  "type": "tosync",
  "a_sub_aa": 1,
  "a_sub_ab": 2,
  "a_sub_ac": 3,
  "b_ary_0": 1,
  "b_ary_1": 3,
  "b_ary_2": 7
}