how to insert record in mysql with unique column value using slick api in play framework

Question

I am new to scala-play framework. I am using Play framework 2.5 and play-slick 1.1.1. I am confused in Future return type when using Action to handle request. I am getting this error:

found : scala.concurrent.Future[play.api.mvc.Result] required: play.api.mvc.Result

in my registerUser method.

This is my registerUser method

def registerUser = Action.async { implicit request =>

registerForm.bindFromRequest.fold(

  errorForm => {
    Future.successful(Ok(views.html.registration(errorForm)))
  },

  user => {
    userDal.isExists(user.email).map { isExists =>

      if(isExists.booleanValue() == false){
        Redirect(routes.UserController.login()).flashing("message"->"Invalid Credential")
      }
      **else{
          userDal.registerUser(user.firstname, user.lastname, user.email, user.password, user.address).map { _ =>

          Redirect(routes.ProductController.index()).withSession("username" -> user.firstname)
        }**
      }
    }
  }
 )
}

Here is my table projection and method to insert data into user table. In table 'user', column 'email' is marked as a unique.

Table:

private class UserDB(tag: Tag) extends Table[User](tag, "user") {

def id = column[Option[Int]]("id", O.PrimaryKey, O.AutoInc)

def firstname = column[String]("firstname")

def lastname = column[String]("lastname")

def email = column[String]("email")

def password = column[String]("password")

def addr = column[String]("address")

override def * = (id, firstname, lastname, email, password, addr) <> ((User.apply _).tupled, User.unapply)
}

method to insert in user table

def registerUser(fname: String, lname: String, email: String, password: String, addr: String): Future[User] = db.run {

(userTable.map(u => (u.firstname, u.lastname, u.email, u.password, u.addr))

  returning userTable.map(_.id)
  // And we define a transformation for the returned value, which combines our original parameters with the

  into ((column, id) => User(id, column._1, column._2, column._3, column._4, column._5))) += (fname, lname, email, password, addr)
}

I also have method to check whether user with same email is exists or not. Here is the method

def isExists(email: String): Future[Boolean] = db.run{

userTable.filter(_.email === email).exists.result
}

If I don't check for existing email through 'isExists' method then it throws SQLException for unique constraints.

Thank you very much in advance.

It's not clear where the error is coming from. Can you note the line where this is thrown? From the message, it's also a simple type error - you either need to change a method signature, or else map the value of the `Future`. — jkinkead, Apr 22 '16 at 16:17
Thank you @jkinkead, for replying. In 'registerUser' (first one from the top) method, i have put code in ** code ** which one throws an error mentioned in question. — Govardhan, Apr 23 '16 at 06:40
Try wrapping the first `Redirect` in `Future.successful`. The two branches of your `if / else` result in different types. — jkinkead, Apr 26 '16 at 18:56

score 0 · Answer 1 · answered Apr 30 '16 at 02:33

The error is caused by the use of map on userDal.isExists(user.email). The if / else statement is generating a Future[Redirect], but the map call needs an instance of Redirect.

In this case, the easiest solution is to replace map with flatMap, which expects an instance of Future[Redirect].

how to insert record in mysql with unique column value using slick api in play framework

1 Answers1