Scala / Slick 3.0.1 – 更新多个列

发布时间：2020-12-16 18:01:55 所属栏目：安全来源：网络整理

导读：每当我收到给定id的更新请求时,我都会尝试更新DB表中的masterId和updatedDtTm列(我不想更新我的createdDtTm).以下是我的代码： case class Master(id:Option[Long] = None,masterId:String,createdDtTm:Option[java.util.Date],updatedDtTm:Option[java.util

每当我收到给定id的更新请求时,我都会尝试更新DB表中的masterId和updatedDtTm列(我不想更新我的createdDtTm).以下是我的代码：

case class Master(id:Option[Long] = None,masterId:String,createdDtTm:Option[java.util.Date],updatedDtTm:Option[java.util.Date])

/**
 * This is my Slick Mapping table
 * with the default projection
 */
`class MappingMaster(tag:Tag) extends
Table[Master](tag,"master") {

    implicit val DateTimeColumnType = MappedColumnType.base[java.util.Date,java.sql.Timestamp](
    {
      ud => new Timestamp(ud.getTime)
    },{
      sd => new java.util.Date(sd.getTime)
    })
    def id = column[Long]("id",O.PrimaryKey,O.AutoInc)
    def masterId = column[String]("master_id")
    def createdDtTm = column[java.util.Date]("created_dttm")
    def updatedDtTm = column[java.util.Date]("updated_dttm")

    def * = (id.?,masterId,createdDtTm.?,updatedDtTm.?) <>
      ((Master.apply _).tupled,Master.unapply _) }

/**
 * Some where in the DAO update call
 */
db.run(masterRecords.filter(_.id === id).map(rw =>(rw.masterId,rw.updatedDtTm)).
update(("new_master_id",new Date()))

// I also tried the following
db.run(masterRecords.filter(_id === id).map(rw => (rw.masterId,rw.updatedDtTm).shaped[(String,java.util.Date)]).update(("new_master_id",new Date()))

Slick的文档指出,为了更新多个列,需要使用map来获取相应的列,然后更新它们.

这里的问题如下 – 更新方法似乎接受Nothing的值.

我也试过以下做同样的事情：

val t = for {
ms <- masterRecords if (ms.id === "1234")
} yield (ms.masterId,ms.updateDtTm)
db.run(t.update(("new_master_id",new Date())))

当我编译代码时,它给了我以下编译异常：

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: slick.lifted.FlatShapeLevel
[error]      Source type: (slick.lifted.Rep[String],slick.lifted.Rep[java.util.Date])
[error]    Unpacked type: (String,java.util.Date)
[error]      Packed type: Any
[error]     db.run(masterRecords.filter(_id === id).map(rw => (rw.masterId,new Date()))

我使用Scala 2.11与Slick 3.0.1和IntelliJ作为IDE.真的很感激,如果你能对此有所了解.

干杯,
Sathish所在

解决方法

(取代原始答案)似乎隐含必须在查询的范围内,这编译：

case class Master(id:Option[Long] = None,updatedDtTm:Option[java.util.Date])

implicit val DateTimeColumnType = MappedColumnType.base[java.util.Date,java.sql.Timestamp](
  {
    ud => new Timestamp(ud.getTime)
  },{
    sd => new java.util.Date(sd.getTime)
  })

class MappingMaster(tag:Tag) extends Table[Master](tag,"master") {


    def id = column[Long]("id",O.AutoInc)  
    def masterId = column[String]("master_id")
    def createdDtTm = column[java.util.Date]("created_dttm")
    def updatedDtTm = column[java.util.Date]("updated_dttm")

    def * = (id.?,updatedDtTm.?) <> ((Master.apply _).tupled,Master.unapply _)

}

private val masterRecords = TableQuery[MappingMaster]

val id: Long = 123

db.run(masterRecords.filter(_.id === id).map(rw =>(rw.masterId,rw.updatedDtTm)).update("new_master_id",new Date()))

val t = for {
  ms <- masterRecords if (ms.id === id)
} yield (ms.masterId,ms.updatedDtTm)
db.run(t.update(("new_master_id",new Date())))

（编辑：李大同）

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