3

我在 Scala Playframework 中有一个数据库表定义为

CREATE TABLE account (
    id     SERIAL,
    email  TEXT  NOT NULL,
    buffer BYTEA NOT NULL,
    PRIMARY KEY (id)
);

我正在使用协议缓冲区使用以下代码将对象序列化为字节数组

DB.withConnection{ implicit c=>
  SQL("INSERT INTO device (buffer,secret) VALUES ({secret},{buffer})").on(
    "secret"->device.getSecret(),
    "buffer"->device.toByteArray()
  ).executeInsert()
}

返回的类型device.toByteArray()应该Array[Byte]与该列的数据库类型匹配。但是在执行我得到的代码后

play.core.ActionInvoker$$anonfun$receive$1$$anon$1: Execution exception [[PSQLException: ERROR: column "buffer" is of type bytea but expression is of type character varying
  Hint: You will need to rewrite or cast the expression.
  Position: 44]]
    at play.core.ActionInvoker$$anonfun$receive$1.apply(Invoker.scala:134) [play_2.9.1.jar:2.0.3]
    at play.core.ActionInvoker$$anonfun$receive$1.apply(Invoker.scala:115) [play_2.9.1.jar:2.0.3]
    at akka.actor.Actor$class.apply(Actor.scala:318) [akka-actor.jar:2.0.2]
    at play.core.ActionInvoker.apply(Invoker.scala:113) [play_2.9.1.jar:2.0.3]
    at akka.actor.ActorCell.invoke(ActorCell.scala:626) [akka-actor.jar:2.0.2]
    at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:197) [akka-actor.jar:2.0.2]
Caused by: org.postgresql.util.PSQLException: ERROR: column "buffer" is of type bytea but expression is of type character varying
4

1 回答 1

4

查看anorm 源代码和Postgres 文档，您似乎需要添加一个处理程序以Array[Byte]正确存储使用setBytes而不是setObject当前代码所要求的。

我会在框架中的 anyParameter 中扩展匹配以读取

    value match {
      case Some(bd: java.math.BigDecimal) => stmt.setBigDecimal(index, bd)
      case Some(b: Array[Byte]) => stmt.setBytes(index, b)
      case Some(o) => stmt.setObject(index, o)
      // ...

并添加

implicit val byteArrayToStatement = new ToStatement[Array[Byte]] {
  def set(s: java.sql.PreparedStatement, index: Int, aValue: Array[Byte]): Unit = setAny(index, aValue, s)
}

您应该可以在框架之外通过这里工作的类型类魔法来执行此操作，但我现在没有时间弄清楚这一点。

于 2012-08-17T07:16:32.993 回答