Parameters don't work with VB.NET

[sorenjakobsen]

Basic VB.NET/LINQ queries such as the following do not seem to work with efcore.pg.

Dim email = "[email protected]"
Dim p = (New MyDbContext).Person.Single(Function(x) x.Email = email)

I get the following error message.

'42703: column "__$vb$local_email_0" does not exist

[roji]

@sorenjakobsen can you please open this in the EF repo? This doesn't seem like something that's specific to the PG provider.

[sorenjakobsen]

I don't have this problem with the standard SQL Server provider, so I don't think it is a general EF problem?

[roji]

@sorenjakobsen then can you please post a minimal, runnable VB console program that fails when using PostgreSQL, but works when using SQL Server?

[sorenjakobsen]

@roji yes, here is an example, should be runnable with Visual Studio (Community) 2022.

ConsoleApp2.zip

[roji]

Thanks, I'll take a look at this soon.

[roji]

Thanks @sorenjakobsen, I could reproduce the problem thanks to your code sample and understand the problem - it's a somewhat complex interplay between how the VB compiler names captured members, and how Npgsql/PG handle parameter names. I've opened dotnet/efcore#33150 to fix this on the EF side, and have submitted dotnet/efcore#33151 to fix it. Unfortunately, it's unlikely the fix will make it into 8.0 (this is the first time we've had this bug raised, so very few people seem to be trying VB with EF and PG).

I'll go ahead and close this issue here - you can comment on dotnet/efcore#33150.