Do System.Linq.Expressions support 'IS DISTINCT FROM' and 'IS NOT DISTINCT FROM' with npgsql/postgres?

[cirrusone]

Postgres supports statements IS DISTINCT FROM and IS NOT DISTINCT FROM which is a much nicer handling of null values, especially when inverting expressions using NOT. Pg wiki - IS DISTINCT FROM

DISTINCT here is different to what '<>' or '!=" tests for.

Are these statements currently supported by System.Linq.Expressions?

If not, is it something that's likely to be supported in the near future?

It would be a really useful feature to include in both Npgsql and System.Linq.Expressions and massively help with filter logic where currently applying NOT to an existing filter excludes null values and complicates building queries to handle where you do genuinely need to return nulls.

Edit: I didn't realise when I posted this that SQL Server 2022 now support these predicates too IS [NOT] DISTINCT FROM (Transact-SQL)

[huoyaoyuan]

It is not something for System.Linq.Expressions, but for providers like Npgsql.

Generally, for custom or extended functionalities, the LINQ-to-SQL provider can expose some custom functions. The functions are encoded as calls in compiled expression tree, and the provider recognizes the calls and translates to corresponding SQL.

Like functions listed here, Npgsql can expose functions that maps to those.

[roji]

Indeed, this question doesn't belong in dotnet/runtime; it's a SQL translation question, and so belongs in EF, or even the specific EF provider(s) in question.