从 scalaquery 到 Slick 3.1 - .list 已删除？

Question

我正在尝试从 scalaquery 迁移到 slick 3，但在编译时出现以下错误：

Error:(107, 19) No matching Shape found.
Slick does not know how to map the given types.
Possible causes: T in Table[T] does not match your * projection. Or you use an unsupported type in a Query (e.g. scala List).
  Required level: slick.lifted.FlatShapeLevel
     Source type: slick.lifted.ProvenShape[TestData]
   Unpacked type: T
     Packed type: G
        (for (test <- testTable)
                  ^

这是改动前的相关代码：

case class TestData(id: Int, test_double: Double)

object TestTable extends Table[TestData]("Test_Table") {
  var test_value = ""
  def id = column[Int]("ID_Test", O.PrimaryKey, O.AutoInc)
  def nep_column = column[Double](test_value)
  def * = id ~ nep_column <> (TestData, TestData.unapply _)
}

def get_data = {
    db withSession {
            for (test <- testTable)
            yield test.*
          }.list
}

这是我修改后的：

case class TestData(id: Int, test_double: Double)

class TestTable(tag: Tag) extends Table[TestData](tag, "Test_Table") {
  def id = column[Int]("ID_Test", O.PrimaryKey, O.AutoInc)
  def nep_column = column[Double](test_value)
  def * = (id, nep_column) <> ((TestData.apply _).tupled, TestData.unapply)
}

object testTable extends TableQuery(new TestTable(_)) {
  var test_value = ""
}

def get_data = {
    Await.result(db.run(
        (for (test <- testTable)
          yield test.*).result), Duration.Inf)
}

因此，简单地将 .list 替换为 .result 似乎不起作用。我再也找不到 Slick 3 中对 .list 的任何引用。被移除了吗？

有谁知道我这里有什么问题以及如何解决？

Answer 1

你根本不需要使用 for comprehension:

def get_data: Seq[TestData] = Await.result(db.run(testTable.result), Duration.Inf)

从 scalaquery 到 Slick 3.1 - .list 已删除？

From scalaquery to Slick 3.1 - .list removed?

scala

slick