Slick/Scala: What is a Rep[Bind] and how do I turn it into a value?

Question

I\'m trying to figure out Slick (the Scala functional relational model). I\'ve started to build a prototype in Slick 3.0.0 but of course... most of the documentation is eith

Answer 1

Rep[] is a replacement to the Column[] datatype used in slick .

users.map(_.id) returns values of the Column('n_user_id') for all rows

val result : Rep[Long] = users.map(_.id)

users.map(_.id) // => select n_user_id from app_dat_user_t;

The obtained value is of type Column[Long] [ which is now Rep[Long] ]. You cannot directly print values of the above resultSet as it is not of any scala collection type

• You can first convert it to some scala collection and then print it as below :

  var idList : List[Long] = List()
  users.map(_.id).forEach(id =>
  idList = idList :+ id
  )
  

  println(idList)** // if you need to print all ids at once

• else you can simply use :

  users.map(_.id).forEach(id =>
  println(id)
  ) // print for each id
  

And ,

val users = TableQuery[UserModel] // => returns Query[UserModel, UserModel#TableElementType, Seq])

val users = for (user <- users) yield user // => returns Query[UserModel, UserModel#TableElementType, Seq])

both mean the same , So you can directly use the former and remove the latter