DocumentDB calls a stored procedure from another stored procedure or itself

Question

Is there a way to call stored procedures (or even UDF, if they work) recursively with DocumentDB documents?

We have a document that looks something like this:

{ "docID" : "my_id", "owner" : "fred", "items" : [ { "itemID" : "1", "type" : "item", "value" : 3 }, { "itemID" : "2", "type" : "group", "items" : [ { "itemID" : "2.1", "type" : "group", "items" : [ { "itemID" : "2.1.1", "type" : "item", "value" : 2 }, { "itemID" : "2.1.2", "type" : "item", "value" : 4 } ] }, { "itemID" : "2.2", "type" : "item", "value" : 1 } ] } ] } 

Each time we have "items" , the "items" array can contain entries that are a combination of "type" : "item" and "type" : "group" . Entries that have a value of "type" : "item" have a simple "value" field that needs to be summarized. Entries with "type" : "group" have an array of "items" ... and so on. Theoretically, there is no limit to the level of recursion, which I recognize as a problem, but in practice the levels will rarely be below 4 or 5 depths.

The pseudocode for what I'm trying to write looks something like this:

 function sumValues(items) { int total = 0; forEach(item in items) { if (item.type == "item") { total += item.value; } else { total += sumValues(item.items); } } return total; } function sumAllValues() { var ctx = getContext(); var coll = ctx.getCollection(); var response = ctx.getResponse(); // query for docs by owner var filterQuery = 'SELECT * FROM Docs d where d.owner = \\\"fred\\\"'; var done = coll.queryDocuments(coll.getSelfLink(), filterQuery, {}, function (err, docs, options) { if (err) throw new Error ('Error' + err.message); var total = 0; docs.forEach(function(doc) { total += sumTotals(doc.items); }); response.setBody('Total: ' + total); }); } 

Is it possible? Does DocumentDB support calling sproc from another sproc? Can sproc call itself?

I found several links to DocumentDB stored procedures on the Internet, including this and this and and, as well as many other pages.

If possible, I think that I may have to somehow request a collection to get the sproc that I want to call, and then somehow reference the sproc, and not just call sumTotals() directly, as with a stand-alone language.

We are just starting to look at programming with DocumentDB, so we are not entirely sure what can be done with it. Thanks for any help or advice.

Answer 1

I think you're on the right track here.

Cannot execute stored procedure from stored procedure.

However, it can define JS functions within a stored procedure that can be referenced, called, and reused from this stored procedure.

In this case, simply define your sumValues() function inside the parent stored procedure sumAllValues() (as well as the swapItems() example you mentioned).

 function sumAllValues() { var ctx = getContext(); var coll = ctx.getCollection(); var response = ctx.getResponse(); // query for docs by owner var filterQuery = 'SELECT * FROM Docs d where d.owner = \\\"fred\\\"'; var done = coll.queryDocuments(coll.getSelfLink(), filterQuery, {}, function (err, docs, options) { if (err) throw new Error ('Error' + err.message); var total = 0; docs.forEach(function(doc) { total += sumValues(doc.items); }); response.setBody('Total: ' + total); }); function sumValues(items) { int total = 0; items.forEach(function(item) { if (item.type == "item") { total += item.value; } else { total += sumValues(item.items); } }); return total; } } 

You can also define UDFs for the logic you want to split and reuse for multiple stored procedures and queries.