Batched upsert

[dullbananas]

This could be done by adding a set_excluded function that takes an AsChangeset implementation and applies excluded to the columns that don't have the corresponding field set to None

diesel::insert_into(bunny::table)
    .values(&new_bunnies)
    .on_conflict(id)
    .do_update()
    .set(set_excluded(&new_bunnies))

Edit: actually this idea doesn't work because the items in new_bunnies could have varying Some or None values, but another thing that could be done which is not exactly the same is set_excluded(bunny::all_columns)

[weiznich]

For Feature Request proposals we expect quite a lot more details than: "I want to have this or that".

I would expect at least the following information:

• How does the exact proposed API look like
• What invariants need to be uphold
• What database systems support this syntax
• How would this be implemented (You don't need to provide a complete implementation, but you should at least cover some sketch how something can be represented in the type system)