CosmosDB - Entity Framework Core - Contains could not be translated

[patrickdgt]

I try to manipulate a CosmosDB (SQL) using entity framework core 3.0. Everything works fine except when I try to use Contains

For example:

var query = _context.Challenges.Where(c => c.Name.Contains( "string"));

EF is supposed to translate it to the following SQL (that works perfectly on the CosmosDB – Query Explorer)

SELECT * FROM c WHERE CONTAINS(c.Name, "string")

But I receive the following error message:

The LINQ expression 'Where(\n source: DbSet, \n predicate: (c) => c.Name.Contains("string"))' could not be translated.
Either rewrite the query in a form that can be translated, or switch to client evaluation explicitly by inserting a call to either AsEnumerable(), AsAsyncEnumerable(), ToList(), or ToListAsync().
See https://go.microsoft.com/fwlink/?linkid=2101038 for more information.

Of course, I don’t want to code it like the following, that will execute the entire contains on the client, just to make a simple LIKE…

List entities = _context.Challenges.AsEnumerable().Where(c => c.Name.Contains( "string")).ToList();

Any idea of to evaluate the "contains" on the server side ?

Note: I try the exact same code using UseSqlServer rather than UseCosmos (and by adding the needed [Key] annotation and creating a SQL server) and it works like a charm.... So I think it's a definitively a CosmosDB vs EF issue.

EF Core version:
Database provider: Microsoft.EntityFrameworkCore.Cosmos
Target framework: NET Core 3.0.0
Operating system: OS X Windows 10 (try both)
IDE: Last stable version on both OSX and Windows 10

Thanks in advance for your help.

[smitpatel]

Duplicate of #16143

[ajcvickers]

Note from triage: do the 3.1 relational fix for Cosmos.

[krw1010]

Any further info on this? I'm encountering the same error in .NET Core 3.1. @ajcvickers What is the relational fix you mentioned?

var user = await Context.Users.Where(x => x.email.Contains("string")).FirstOrDefaultAsync();

System.InvalidOperationException
HResult=0x80131509
Message=The LINQ expression 'DbSet
.Where(a => a.Email.Contains(__search_0))' could not be translated. Either rewrite the query in a form that can be translated, or switch to client evaluation explicitly by inserting a call to either AsEnumerable(), AsAsyncEnumerable(), ToList(), or ToListAsync(). See https://go.microsoft.com/fwlink/?linkid=2101038 for more information.
Source=Microsoft.EntityFrameworkCore

[xtellurian]

I'm also seeing this error in 3.1

[nickwilsonr]

Still an issue in 3.1.1.. It looks like the solution has been merged though, so when can we expect it to be released?

[ajcvickers]

@AndriySvyryd @smitpatel Difference between #16143 and this issue?

[AndriySvyryd]

This is a subset.
Fixed in 83dccdc