我是 Slick 的新手,很难将 java.sql.date/time/timestamp 的映射映射到 jodatime。
trait ColumnTypeMappings {
val profile: JdbcProfile
import profile.api._
val localTimeFormatter = DateTimeFormat.forPattern("HH:mm:ss")
val javaTimeFormatter = new SimpleDateFormat("HH:mm:ss")
implicit val myDateColumnType = MappedColumnType.base[LocalDate, Date](
ld => new java.sql.Date(ld.toDateTimeAtStartOfDay(DateTimeZone.UTC).getMillis),
d => new LocalDateTime(d.getTime).toLocalDate
)
implicit val myTimeColumnType = MappedColumnType.base[LocalTime, Time](
lt => new java.sql.Time(javaTimeFormatter.parse(lt.toString(localTimeFormatter)).getTime),
t => new LocalTime(t.getTime)
)
implicit val myTimestampColumnType = MappedColumnType.base[DateTime, Timestamp](
dt => new java.sql.Timestamp(dt.getMillis),
ts => new DateTime(ts.getTime, DateTimeZone.UTC)
)
}
在自动生成的 Tables.scala 中,我包含了这样的映射:
trait Tables extends ColumnTypeMappings {
val profile: slick.driver.JdbcDriver
import profile.api._
import scala.language.implicitConversions
// + rest of the auto generated code by slick codegen
}
总结一下,我是这样使用的:
object TestTables extends Tables {
val profile = slick.driver.MySQLDriver
}
import Tables._
import profile.api._
val db = Database.forURL("url", "user", "password", driver = "com.mysql.jdbc.Driver")
val q = Company.filter(_.companyid === 1).map(._name)
val action = q.result
val future = db.run(action)
val result = Await.result(future, Duration.Inf)
我得到一个 NullPointerException on: implicit val myDateColumnType.... 运行它时。如果删除映射,我已经验证了最后一段代码是否有效。
最佳答案
尝试在 MappedColumnTypes
的定义中将 implicit val
更改为 implicit def
。之所以与Maksym Chernenko给出的答案有关对此question .通常,尚未注入(inject) JdbcProfile
驱动程序(定义 api.MappedColumnType
),并且:
that causes NPE. You can either make your "mapper"
val
lazy
, or change it fromval
todef
(as shown below)
implicit def myDateColumnType = MappedColumnType.base[LocalDate, Date](
ld => new java.sql.Date(ld.toDateTimeAtStartOfDay(DateTimeZone.UTC).getMillis),
d => new LocalDateTime(d.getTime).toLocalDate
)
implicit def myTimeColumnType = MappedColumnType.base[LocalTime, Time](
lt => new java.sql.Time(javaTimeFormatter.parse(lt.toString(localTimeFormatter)).getTime),
t => new LocalTime(t.getTime)
)
implicit def myTimestampColumnType = MappedColumnType.base[DateTime, Timestamp](
dt => new java.sql.Timestamp(dt.getMillis),
ts => new DateTime(ts.getTime, DateTimeZone.UTC)
)
关于scala - 映射列类型 Slick 3.1.1,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/35451513/