TableQuery to List of case-class

Question

I have a play application which uses slick 3 for querying Mysql DB underneath: I have defined a User case class and Users as below:

    case class User(id: Option[Int], first: String, last: String)

    class Users(tag: Tag) extends Table[User](tag, "users") {
      def id = column[Int]("id", O.PrimaryKey, O.AutoInc)
      def first = column[String]("first")
      def last = column[String]("last")
      def * = (id.?, first, last) <> (User.tupled, User.unapply)
    }
val users = TableQuery[Users]

Now when I query the Users with last name 'Smith'. This is how it looks like

val usersTab = users.filter(usr => usr.last === 'Smith').result
val userList:List[User] = users.map(usr => User(usr.id,usr.first,usr.last)).toList

Similarly,if I have a List[User] as userList that needs to be added to database. Then,

users.map(usr => (usr.id,usr.first,usr.last))+=((userList(0).id,userList(0).first, userList(0).last)) //Iterate over all element

So I was expecting a much cleaner and concise way of converting List of case class to TableQuery and vice-versa. Is there a better way to do this?

Above solution works well but I have more than a dozen of table that needs to be populated. Then it starts to look ugly and repetitive.

concise way of converting List of case class to TableQuery by this do you mean you want a concise way to write a list of cases classes to the table? — rogue-one
Yes @rogue-one , list of case classes to table and table to list of case classes. — Aiden

rogue-one rogue-one · Accepted Answer · 2017-06-11T20:14:40

writing a list of User class instances to a table can be accomplished using the ++= method as shown below

def insert(data: List[User]) = {
  db.run(users ++= data)
}

Querying based on last name as can be done as shown below. the below method returns a Future of List of User.

def queryLastName(lastName: String): Future[List[User]] = {
  db.run(users.filter(usr => usr.last === lastName).result)
}

TableQuery to List of case-class

1 Answers