Locking PostgreSQL Advice

[HashPong]

Hey,

I am currently using Entity Framework with PostgreSQL server, and I am looking for efficient way to use linq/IQueryable with For Update for retrieved rows/row

There will be no deadlock since I will be sorting rows by key, and only need to lock on returned rows, not all included entities.

But I can't seem to find for update extension anywhere, and typing out SQL raw string queries is not feasible, as it will cause so much work to create/debug, so I want to use IQueryable that has For update attached to returned rows.

I know I could use pg_advisory_lock, but I wouldn't know what rows to lock, as the return query is the one that will apply the locks to fetched rows that require changing.

Atm one way I could do this although very inefficient:

1. Fetch row IDs that require changing.
2. Fetch rows by previously found IDs with for update
3. Check in memory if fetched rows still require changing.

3-step process that could be done in 1… :(

Question: How can I apply ForUpdate to IQueryable? Are there any alternative ways I could achieve returned rows locking? Am I missing something?

My ideal usage: