Kysely is a query builder: you build queries by calling javascript functions, while with pg-typesafe you write SQL directly.
I've used kysely before creating pg-typesafe, and came to the conclusion that writing SQL directly is more convenient.
A query builder works well for simple cases (db.selectFrom("t").where("id","=","1") looks a lot like the equivalent SQL), however, for more complicated queries it all falls apart. I often had to look at the docs to find how to translate some predicate from SQL to the required idiom. Also, I don't think kysely can automatically infer the return type of PostgreSQL functions, while pg-typed does (it asks PostgreSQL for it).
If you're into Haskell prior art, there's postgresql-typed https://hackage.haskell.org/package/postgresql-typed-0.6.2.5... where you write queries, it safely(?) puts in your variables, and you automatically get back typed values.
How is this different from sqlc with sqlc-gen-typescript?
How is this different than kysely + kysely-codegen (or hand-made types)?
Kysely is a query builder: you build queries by calling javascript functions, while with pg-typesafe you write SQL directly.
I've used kysely before creating pg-typesafe, and came to the conclusion that writing SQL directly is more convenient.
A query builder works well for simple cases (db.selectFrom("t").where("id","=","1") looks a lot like the equivalent SQL), however, for more complicated queries it all falls apart. I often had to look at the docs to find how to translate some predicate from SQL to the required idiom. Also, I don't think kysely can automatically infer the return type of PostgreSQL functions, while pg-typed does (it asks PostgreSQL for it).
It only changes the types; not the code.