There is a scenario when the requestType="HR" (which comes from the HTTP PUT request), it should return all the students information but return title as "EMPLOYEE"
For example, consider a "student" table with columns name,id, and title
+-------+----+--------------------+
+ name | id | title +
+-------+----+--------------------+
| KING | 10 | SOFTWARE ENGINEER |
| BLAKE | 30 | SYSTEMS ENGINEER |
+-------+----+--------------------+
GOAL: return all students, and override title="EMPLOYEE"
Here is what I have so far
case class Student(name: String, id: Long, title: String)
class StudentTable(tag: Tag) extends Table[Student](tag, "student") {
def name = column[String]("name")
def id = column[Long]("id")
def title = column[String]("title")
override def * = (name, id, title) <> ((Student.tupled, Student.unapply)
}
lazy val studentsQuery = TableQuery[StudentTable]
When i try to map and change the title value in the query, it complains about "re-assignment to val"
val f = studentsQuery.map(p => p.title = "EMPLOYEE).result
complier error: Reassignment to val
Approach 2: I tried to pass in the requestType as a function parameter to the StudentTable, so that I can modify the title value based on the requestType. But then was not able to define studentsQuery since it was complaining about the "required tag".
class StudentTable(tag: Tag)(reqType: String) extends Table[Student](tag, "student") {
def name = column[String]("name")
def id = column[Long]("id")
def title = req.type match {
case "HR" => "EMPLOYEE"
case _ => column[String]("title")
}
override def * = (name, id, title) <> ((Student.tupled, Student.unapply)
}
// Didn't understand how to provide tag
lazy val studentsQuery = TableQuery[StudentTable]()("HR")
compilation error: unspecified value parameters: Cons: (Tag) => StudentTable
I wasn't able to do it from Slick, but found a way to do it using json serialization.
import scala.concurrent.Await
import scala.concurrent.duration._
import slick.driver.MySQLDriver.api._
case class Student(name: String, id: Long, title: String)
class StudentTable(tag: Tag) extends Table[Student](tag, "student") {
def name = column[String]("name")
def id = column[Long]("id")
def title = column[String]("title")
override def * = (name, id, title) <> ((Student.tupled,Student.unapply)}
lazy val studentsQuery = TableQuery[StudentTable]
implicit def StudentDataWrites = new Writes[Student] {
def writes(student: Student) =
Json.obj(
"name" -> student.name,
"id" -> student.id,
"title" -> "EMPLOYEE"
)
}
def getStudentsInfo() = Action {
val students= Await.Result(db.run(studentsQuery.size.result), 10.seconds)
Ok(Json.obj("students" -> Json.toJson(students)))
}