CosmosDB sort results by a value into an array - azure

Question

I've some CosmosDB documents like the following
{
"ProductId": 1,
"Status": true,
"Code": "123456",
"IsRecall": false,
"ScanLog": [
{
"Location": {
"type": "Point",
"coordinates": [
13.5957758,
42.7111538
]
},
"TimeStamp": 201602160957190600,
"ScanType": 0,
"UserId": "1004"
},
{
"Location": {
"type": "Point",
"coordinates": [
13.5957907,
42.7111359
]
},
"TimeStamp": 201602161246336640,
"ScanType": 0,
"UserId": "1004"
}
]
}
How can I order the query results by the TimeStamp property? I've tried using this query
SELECT c.Code, b.TimeStamp FROM c JOIN b IN c.ScanLog ORDER BY b.TimeStamp
but I receive this error
Order-by over correlated collections is not supported.
What is the correct way to do this?

Answer 1

JOINs with ORDER BY are currently not supported.
However, here is a user defined function (UDF) that will do the trick:
function sortScanLog (scanLog) {
function compareTimeStamps(a, b) {
return a.TimeStamp - b.TimeStamp;
}
return scanLog.sort(compareTimeStamps);
}
You use with a query like this:
SELECT c.ProductId, udf.sortScanLog(c.ScanLog) as ScanLog FROM c
If you want the opposite sort order, simply swap the a and b. So, the signature of the compareTimeStamps inner function would be:
function compareTimeStamps(b, a)
Alternatively, you can sort client-side after the results are returned.

Answer 2

Right now, ORDER BY clauses mixed with JOINs are not supported, the engine can look at indexed properties for JOIN operations but cannot re-order results based on the JOIN result.
You'd have to go with something like Larry offered or do the JOIN on the Query and the Sort by your own code once the results arrive, if you use C#, you can sort them with Linq for example.