when inserting I want a way to set the "conflict" behavior.

[lex148]

Discussed in #173

^{Originally posted by bbenne10 February 26, 2026}
Currently, I don't see a great way to ignore conflicts on insert.

I have a File table that looks like this:

#[derive(Clone, Debug, Default, Eq, Hash, PartialEq)]
pub struct Sha256Sum([u8; SHA256_BYTE_LEN]);

// And some traits to make sqlx happy...
impl sqlx::Type<sqlx::Postgres> for Sha256Sum {...}
impl<'r> sqlx::Decode<'r, sqlx::Postgres> for Sha256Sum {...}
impl<'q> sqlx::Encode<'q, sqlx::Postgres> for Sha256Sum {...}


#[derive(WeldsModel)]
struct File {
  sha256: Sha256Sum,
  bytes: Vec<u8>,
}

Asking the DB if this File exists has a race condition (as we're not using linearizable transactions), so we currently write some manual SQL to ignore the failure to insert if the sha256 collides:

INSERT INTO file(sha256, bytes) VALUES (?, ?) ON CONFLICT (sha256) DO NOTHING

But raw SQL is a code smell (as it means you're not able to use the type system to tell immediately if the currently represented schema is upheld in all consuming code), so I would like to back this code out if possible. I see no way to currently be able to do this.

Does such a thing exist?

[bbenne10]

To be clear: Our use case is not bulk. We simply don't need to store duplicate files and someone may upload the same one multiple times. We're going to work towards backing out the need for storing data like this in the database, but for now we already have a highly available data store: it just happens to be postgres :P

[starsoccer]

+1 on a way to handle conflicts. Have a few tables where I need to insert or update(upsert) data on a conflict like this