Question

我有一张表user_permissions，其中包含46个权限列以及id和created_date。此表具有相应的UserPermissions类：

class UserPermission(val id: Long,
  val createdDate: Option[Timestamp],
  val permission1: Boolean,
  val permission2: Boolean,
  ...
  val permission46: Boolean)

和光滑的映射表

class UserPermissions(tag: Tag) extends Table[UserPermission](tag, "users_permissions") {
  def * = (
    id ::
    createdDate ::
    permission1 ::
    permission2 ::
    ...
    permission46 ::
    HNil).shaped <> (
    { case x => UserPermission(
         x(0), x(1), x(2), ... x(47))
    },
    {
       UserPermission.unapply _
    }
  }
  ... <columns defined here>
)

现在我想更新由id标识的UserPermission集。我的功能是：

object UserPermissions {
  val userPermissions = TableQuery[UserPermissions]

  def update(userPermission: UserPermission)(implicit session: Session) = {
    userPermissions.filter(_.id === userPermission.id.get).update(userPermission)
  }
}

这不起作用并抛出异常：

play.api.Application$$anon$1: Execution exception[[SQLServerException: Cannot update identity column 'id'.]]

这有意义，因为Slick生成的SQL是：

update "users_permissions" set "id" = ?, "created_date" = ?, ...

问题1 所以我的第一个问题是我无法使用光滑的更新完整的UserPermission对象。 如果我能解决这个问题，那就太棒了。

由于我无法更新完整对象，因此我想yield要更新的列然后触发更新查询。代码如下所示：

def update(obj: UserPermission)(implicit session: Session) = {
    val query = for {
      p <- userPermissions
      if p.id === obj.id.get
    } yield (p.permission1, p.permission2, ... p.permission46)
    query.update(obj.permission1, obj.permission2, ... obj.permission46)
}

问题2 现在光滑不会更新query.update()功能中的46列。它一次只能处理22列。如何更新我的UserPermissions对象？

我能想到的一个不好的解决方案是第一次更新22次，然后是22秒，然后是第三次查询中的2次。它将是我不想要的3 db更新查询。

我的问题的任何解决方案？

依赖关系是：

scalaVersion := "2.11.4"

"com.typesafe.play" %% "play-slick" % "0.8.1"
"com.typesafe.slick" %% "slick-extensions" % "2.1.0"

Answer 1

Stefan Zeiger，Slick领导，said我们无法做到。但他建议我们在平面22+列表中嵌套投影：

<script src="//cdn.jsdelivr.net/ractive/0.7.3/ractive-legacy.min.js"></script>

<main></main>

<script id='template' type='text/ractive'>
    <label>
        <input type='checkbox' checked='{{variable}}'/> variable ({{variable}})
    </label>
    
    <button type="button" on-click="callMethod(variable?'funcOne':'funcTwo')">Click me</button>
</script>

现在是Slick的test，包括version 3的一个。至于更新：

// 2 classes for the nested structure
case class Part(i1: Int, i2: Int, i3: Int, i4: Int, i5: Int, i6: Int)
case class Whole(id: Int, p1: Part, p2: Part, p3: Part, p4: Part)

// Note that it's a Table[Int] -- we only map the primary key in *
object T extends Table[Int]("t_wide") {
  def id = column[Int]("id", O.PrimaryKey)
  def p1i1 = column[Int]("p1i1")
  def p1i2 = column[Int]("p1i2")
  def p1i3 = column[Int]("p1i3")
  def p1i4 = column[Int]("p1i4")
  def p1i5 = column[Int]("p1i5")
  def p1i6 = column[Int]("p1i6")
  def p2i1 = column[Int]("p2i1")
  def p2i2 = column[Int]("p2i2")
  def p2i3 = column[Int]("p2i3")
  def p2i4 = column[Int]("p2i4")
  def p2i5 = column[Int]("p2i5")
  def p2i6 = column[Int]("p2i6")
  def p3i1 = column[Int]("p3i1")
  def p3i2 = column[Int]("p3i2")
  def p3i3 = column[Int]("p3i3")
  def p3i4 = column[Int]("p3i4")
  def p3i5 = column[Int]("p3i5")
  def p3i6 = column[Int]("p3i6")
  def p4i1 = column[Int]("p4i1")
  def p4i2 = column[Int]("p4i2")
  def p4i3 = column[Int]("p4i3")
  def p4i4 = column[Int]("p4i4")
  def p4i5 = column[Int]("p4i5")
  def p4i6 = column[Int]("p4i6")
  // This is just the default projection -- It doesn't have to contain all columns
  def * = id
  // Instead, we use nested tuples for a full projection:
  def all = (
    id,
    (p1i1, p1i2, p1i3, p1i4, p1i5, p1i6),
    (p2i1, p2i2, p2i3, p2i4, p2i5, p2i6),
    (p3i1, p3i2, p3i3, p3i4, p3i5, p3i6),
    (p4i1, p4i2, p4i3, p4i4, p4i5, p4i6)
  )
  // And override create_* to get the DDL for all columns.
  // Yeah, this is ugly. It used to be much simpler in ScalaQuery.
  // We can add a helper method to simplify it.
  override def create_* =
    all.shaped.packedNode.collect {
      case Select(Ref(IntrinsicSymbol(in)), f: FieldSymbol) if in == this => f
    }.toSeq.distinct
}

T.ddl.create
// Insert into T.all. The extra ".shaped" call is needed because we cannot
// get the types in an implicit conversion due to SI-3346
T.all.shaped.insert(
  0,
  (11, 12, 13, 14, 15, 16),
  (21, 22, 23, 24, 25, 26),
  (31, 32, 33, 34, 35, 36),
  (41, 42, 43, 44, 45, 46)
)

// Get the nested tuples in a query
val q1 = T.map(_.all)
println(q1.first)

// Map the result to the case classes
val i2 = q1.mapResult { case (id, p1, p2, p3, p4) =>
  Whole(id, Part.tupled.apply(p1), Part.tupled.apply(p2), Part.tupled.apply(p3), Part.tupled.apply(p4))
}
println(i2.first)

带有Slick投影的嵌套对象可以为您引入的单个对象展平，也可以随身携带。

Answer 2

问题2的一些建议：

你能用Slick 3.0吗？此版本似乎有solution
您能否以这样的方式更改数据库的布局权限是行而不是列？无论如何，这似乎更具扩展性

光滑 - 更新完整对象或超过22列

2 个答案: