Quill SQL Server: Returning via OUTPUT

Besides NDBC Postgres module, the release of Quill 3.5.0 brings an interesting feature for Microsoft SQL Server users: returning via OUTPUT.

The returning feature

Quill has the returning feature, which behaves in different ways, according to the limitations of each database. Postgres has the largest set of functionalities around returning, given that Postgres dialect supports the INSERT ... RETURNING clause:

case class Product(id: Int, description: String, sku: Long)

val q = quote {
  query[Product].insert(lift(Product(1, "My Product", 1011L))).returning(r => (r.id, r.description))
}

ctx.run(q)
// INSERT INTO Product (id, description, sku) VALUES (?, ?, ?) RETURNING id, description

Quite useful. SQL Server supports a very similar feature via OUTPUT clause. The 3.5.0 release brings this feature to Quill as well.

While implementing this feature I’ve found the inspiration to write the post Contributing to Quill, a Pairing Session, so if you are interested in how this feature came to life, there you go :)

INSERT ... OUTPUT

The way to use the new feature in SQL Server is exactly the same:

val q = quote {
  query[Product].insert(lift(Product(1, "SQL Server", 1433L))).returning(r => (r.id, r.description))
}

ctx.run(q)
// INSERT INTO Product (id, description, sku) OUTPUT INSERTED.id, INSERTED.description VALUES (?, ?, ?)

As mentioned before, it is more limited than Postgres returning. While we can even query the return clause in Postgres, the best we can do on SQL Server are arithmetic operations:

val q = quote {
  query[Product].insert(lift(Product(1, "SQL Server", 1433L)))
}

ctx.run(q.returning(r => r.id + 42))
// INSERT INTO Product (id, description, sku) OUTPUT INSERTED.id + 42 VALUES (?, ?, ?)

This is a limitation of SQL Server, so there’s not much Quill can do about it - except for making sure that invalid operations don’t compile.

Do you use Quill with SQL Server? Give us feedback about the new feature!