Scala浮油撰写列类型映射器

Question

我正在使用slick-pg，它为光滑的List和DateTime类型添加了支持（带有暗示）。

不幸的是，我不能使用List[DateTime] - 浮油不理解这些类型的组成，但我已检查它们自己是否正常工作（例如List[Int]和DateTime）。

有没有一种方法可以轻松组成这两个implicits？

Answer 1

尝试添加

implicit def dateTimeList = 
    MappedColumnType.base[List[DateTime], List[Timestamp]](
     _.map(dt => new Timestamp(dt.getMillis)), 
     _.map(ts => new DateTime(ts.getTime)) 
    ) 

以防万一，整个代码编译：

import java.sql.Timestamp 
import org.joda.time.DateTime 
import slick.jdbc.PostgresProfile.api._ 
import slick.lifted.ProvenShape 
import slick.basic.Capability 
import slick.jdbc.JdbcCapabilities 
import com.github.tototoshi.slick.PostgresJodaSupport._ 
import com.github.tminglei.slickpg._ 

object App { 

    trait MyPostgresProfile extends ExPostgresProfile 
    with PgArraySupport 
    with PgDate2Support 
    with PgRangeSupport 
    with PgHStoreSupport 
// with PgPlayJsonSupport 
    with PgSearchSupport 
// with PgPostGISSupport 
    with PgNetSupport 
    with PgLTreeSupport { 
    def pgjson = "jsonb" // jsonb support is in postgres 9.4.0 onward; for 9.3.x use "json" 

    // Add back `capabilities.insertOrUpdate` to enable native `upsert` support; for postgres 9.5+ 
    override protected def computeCapabilities: Set[Capability] = 
     super.computeCapabilities + /*JdbcProfile.capabilities.insertOrUpdate*/ JdbcCapabilities.insertOrUpdate 

    override val api = MyAPI 

    object MyAPI extends API with ArrayImplicits 
     with DateTimeImplicits 
//  with JsonImplicits 
     with NetImplicits 
     with LTreeImplicits 
     with RangeImplicits 
     with HStoreImplicits 
     with SearchImplicits 
     with SearchAssistants { 
     implicit val strListTypeMapper = new SimpleArrayJdbcType[String]("text").to(_.toList) 
//  implicit val playJsonArrayTypeMapper = 
//  new AdvancedArrayJdbcType[JsValue](pgjson, 
//   (s) => utils.SimpleArrayUtils.fromString[JsValue](Json.parse(_))(s).orNull, 
//   (v) => utils.SimpleArrayUtils.mkString[JsValue](_.toString())(v) 
//  ).to(_.toList) 
    } 
    } 

    object MyPostgresProfile extends MyPostgresProfile 

    import MyPostgresProfile.api._ 

    // This can be used instead of slick-joda-mapper library 
// implicit def dateTime = 
// MappedColumnType.base[DateTime, Timestamp](
//  dt => new Timestamp(dt.getMillis), 
//  ts => new DateTime(ts.getTime) 
// ) 

    implicit def dateTimeList = 
    MappedColumnType.base[List[DateTime], List[Timestamp]](
     _.map(dt => new Timestamp(dt.getMillis)), 
     _.map(ts => new DateTime(ts.getTime)) 
    ) 

    case class Record(id: Int, name: String, friends: List[Int], registered: DateTime, visits: List[DateTime]) 

    class RecordTable(tag: Tag) extends Table[Record](tag, Some("public"), "records") { 
    def id: Rep[Int] = column[Int]("id", O.PrimaryKey, O.AutoInc) 
    def name: Rep[String] = column[String]("name") 
    def friends: Rep[List[Int]] = column[List[Int]]("friends") 
    def registered: Rep[DateTime] = column[DateTime]("registered") 
    def visits: Rep[List[DateTime]] = column[List[DateTime]]("visits") 
    def * : ProvenShape[Record] = (id, name, friends, registered, visits) <> (Record.tupled, Record.unapply) 
    } 

    val records: TableQuery[RecordTable] = TableQuery[RecordTable] 
} 

build.sbt

name := "slickdemo" 

version := "0.1" 

scalaVersion := "2.12.3" 

libraryDependencies += "com.typesafe.slick" %% "slick" % "3.2.1" 
libraryDependencies += "org.slf4j" % "slf4j-nop" % "1.7.25" 
libraryDependencies += "com.typesafe.slick" %% "slick-hikaricp" % "3.2.1" 

libraryDependencies += "org.postgresql" % "postgresql" % "42.1.4" 

libraryDependencies += "com.github.tminglei" %% "slick-pg" % "0.15.3" 

libraryDependencies += "joda-time" % "joda-time" % "2.9.9" 
libraryDependencies += "org.joda" % "joda-convert" % "1.9.2" 
libraryDependencies += "com.github.tototoshi" % "slick-joda-mapper_2.12" % "2.3.0" 

基于answer和documentation。

---

2.另外，您可以strListTypeMapper和playJsonArrayTypeMapper后添加

implicit val dateTimeArrayTypeMapper = 
     new AdvancedArrayJdbcType[DateTime]("timestamp", 
      (s) => utils.SimpleArrayUtils.fromString[DateTime](DateTime.parse)(s).orNull, 
      (v) => utils.SimpleArrayUtils.mkString[DateTime](_.toString)(v) 
     ).to(_.toList) 

。