slick-2.0 - 为什么映射到提升查询中的 List 失败并显示 "Slick does not know how to map the given types."？

Question

我正在尝试映射到 List在 Slick 提升查询中，我收到一个编译错误:

No matching Shape found.
[error] Slick does not know how to map the given types.
[error] Possible causes: T in Table[T] does not match your * projection. Or you use an unsupported type in a Query (e.g. scala List).
[error]   Required level: scala.slick.lifted.FlatShapeLevel
[error]      Source type: Seq[String]
[error]    Unpacked type: T
[error]      Packed type: G

为什么在非 Slick 映射操作中，我可以映射到任何类型，而在 Slick 查询中，我可以映射到简单的 Scala 类型，但不能映射到 Scala List ?

Answer 1

尝试

import slick.driver.(yourDB)Driver.api._