Question

我是使用版本3.1.1的Slick ORM的新手，在普通sql的示例中，我没有看到如何检索数据库列http://slick.typesafe.com/doc/3.1.1/sql.html的值。这是我的简单例子

 def listfollowing() = Action.async {


   val selectq=sql"""SELECT model,id from carsDB where id=17""".as[(String,Int)]
   // I would like to get the value of model back and put it in a Var
   // var model= model
    database.run(selectq).map {finished=> 

   // I would like to get the value of model back and put it in a Var
   // var model= model
           Ok(finished.toString())

    }
  }

如何找回列模型的值，以便将其放入var或val ？

Answer 1

当你这样做时：database.run(selectq).map {finished=> ... } finished是Vector[(String,Int)]。如果您确定它只返回一行（因为"... where id=17"），那么您可以使用headOption()并检查其中是否有值（如果没有id的记录则为none 17），如果有 - >返回它否则返回一些错误。代码将是这样的：

def listfollowing() = Action.async {
    val selectq = sql"""SELECT model,id from carsDB where id=17""".as[(String, Int)]
    db.run(selectq).map { finished => 
        finished.headOption match {
            case s: (String, Int) => Ok(s._1)
            case None => Ok("No car found for requested id")
        }
    }
}

sclick orm for scala如何检索数据库列值

1 个答案: