How to convert C# Linq to cosmos query

Question

Hi Everyone!

We have below C# LINQ query to group from a cosmos IQueryable container and then order by some attributes.

var unitPrices = unitPriceContainer.ToList()
.GroupBy(u => new { u.SupplierId, u.Sku, u.SupplierPackSize })
.Select(s => s.OrderByDescending(o => o.CreatedDate).ThenByDescending(t => t.EffectiveFrom).First())
.ToList();

We want to convert this to Cosmos query so that it can be accessible using FeedIterator.

Is there any workaround to have same query converted or just group by. So that, order by can further be queried over the output of group by. Please suggest.

Answer 1

Hi @Juhi Saxena

The Azure Cosmos DB query provider performs a best effort mapping from a LINQ query into a Cosmos DB SQL query. If you want to get the SQL query that is translated from LINQ, use the ToString() method on the generated IQueryableobject.

There is a guide on how convert LINQ to SQL translation in the below Microsoft link.

https://learn.microsoft.com/en-us/azure/cosmos-db/sql/sql-query-linq-to-sql

Hope this will be helpful and serve as a library for you.

Hope to read from you.

Cheers.
Sina