使用光滑的第一步,我有这个表
case class Employee(name: String,last: String,department: Option[Int] = None,id: Option[Int] = None)
class Employees (tag: Tag) extends Table[Employee](tag, "EMPLOYEES") {
// Auto Increment the id primary key column
def id = column[Int]("ID", O.PrimaryKey, O.AutoInc)
def name = column[String]("NAME", O.NotNull)
def last = column[String]("LAST", O.NotNull)
def dept = foreignKey("EMP_FK",deptId,departments)(_.id)
def * = (name,last,deptId.?, id.?) <> (Employee.tupled, Employee.unapply)
val departments = TableQuery[Departments]
}
case class DepartmentManager(id:Int,name:String,manager:String)
case class Department(id:Option[Int],name:String,managerId:Int)
class Departments (tag: Tag) extends Table[Department](tag, "DEPARTMENTS") {
val employees = TableQuery[Employees]
def id = column[Int]("ID", O.PrimaryKey, O.AutoInc)
def name = column[String]("NAME", O.NotNull)
def managerId = column[Int]("MANAGER_ID", O.Nullable)
def manager = foreignKey("EMP_FK",managerId,employees)(_.id)
def * = (id.?,name,managerId) <> (Department.tupled, Department.unapply)
}
但我收到了编译错误:
Query [Nothing,Nothing,Seq]类型的表达式不符合 期望的类型列表[DepartmentManager
我尝试过做这样的事情(只是为了检查,我知道它很糟糕):
def all: List[DepartmentManager] = db.withSession { implicit session =>
val employees = TableQuery[Employees]
val x = for {
(d, e) <- departments join employees
} yield (d.id, d.name, e.name + " " + e.last)
x.iterator.map(t=> DepartmentManager(t._1,t._2,t._3)).toList
}
但它没有给我预期的结果 - 后者的结果(t._1,t._2,t._3)看起来像
(1,Foo,(EMPLOYEES Path @ 1076478352._2).NAME(EMPLOYEES Path @ 1076478352._2).LAST)
请咨询
答案 0 :(得分:0)
case class Employee(name: String, last: String, department: Option[Int] = None, id: Option[Int] = None)
class Employees (tag: Tag) extends Table[Employee](tag, "EMPLOYEES") {
// Auto Increment the id primary key column
val departments = TableQuery[Departments]
def id = column[Int]("ID", O.PrimaryKey, O.AutoInc)
def name = column[String]("NAME", O.NotNull)
def last = column[String]("LAST", O.NotNull)
def deptId = column[Int]("DEPARTMENT", O.NotNull)
def deptFK = foreignKey("EMP_DEP_FK", deptId, departments)(_.id)
def * = (name, last, deptId.?, id.?) <>(Employee.tupled, Employee.unapply)
}
case class DepartmentManager(id: Int, name: String, manager: String)
case class Department(id: Option[Int], name: String, managerId: Int)
class Departments (tag: Tag) extends Table[Department](tag, "DEPARTMENTS") {
val employees = TableQuery[Employees]
def id = column[Int]("ID", O.PrimaryKey, O.AutoInc)
def name = column[String]("NAME", O.NotNull)
def managerId = column[Int]("MANAGER_ID", O.Nullable)
def managerFK = foreignKey("DEP_MAN_FK", managerId, employees)(_.id)
def * = (id.?, name, managerId) <>(Department.tupled, Department.unapply)
}
def all(implicit s: Session): List[DepartmentManager] = {
val employees = TableQuery[Employees]
val x = for {
(d, e) <- departments join employees on (_.managerId === _.id)
} yield (d.id, d.name, e.name + " " + e.last)
x.list.map(t => DepartmentManager(t._1, t._2, t._3))
}
您需要隐式Session
对象才能在查询中调用list
或iterator
方法。