Question

我正在使用scala play 2框架的项目中工作，我使用光滑的FRM和postgres数据库。

在我的项目中，客户是一个实体。所以我也创建了一个客户表和客户案例类和对象。另一个实体是帐户。代码如下所示

case class Customer(id: Option[Int],
                status: String,
                balance: Double,
                payable: Double,
                created: Option[Instant],
                updated: Option[Instant]) extends GenericEntity {
    def this(status: String,
       balance: Double,
       payable: Double) = this(None, status, balance, payable, None, None)
}


class CustomerTable(tag: Tag) extends GenericTable[Customer](tag, "customer"){
    override def id = column[Option[Int]]("id")
    def status = column[String]("status")
    def balance = column[Double]("balance")
    def payable = column[Double]("payable")
    def account = foreignKey("fk_customer_account", id, Accounts.table)(_.id, onUpdate = ForeignKeyAction.Restrict, onDelete = ForeignKeyAction.Cascade)

    def * = (id, status, balance, payable, created, updated) <> ((Customer.apply _).tupled, Customer.unapply)
}

object Customers extends GenericService[Customer, CustomerTable] {
    override val table = TableQuery[CustomerTable]
    val accountTable = TableQuery[AccountTable]
    override def copyEntityFields(entity: Customer, id: Option[Int],
    created: Option[Instant], updated: Option[Instant]): Customer = {
        entity.copy(id = id, created = created, updated = updated)
    }
}

现在问题是如何在客户对象中创建帐户对象？或者我如何获得客户的帐户？

Answer 1

Slick不是ORM它只是一个功能关系映射器。嵌套对象不能直接用于slick Hibernate或任何其他ORMs而是

<强>油滑

//Usual ORM mapping works with nested objects
case class Person(name: String, age: Int, address: Address) //nested object

//With Slick
case class Address(addressStr: String, id: Long) //id primary key
case class Person(name: String, age: Int, addressId: Long) //addressId is the id of the address object and its going to the foreign key

客户中的帐户对象

case class Account(id: Long, ....) // .... means other fields.
case class Customer(accountId: Long, ....)

将accountId放在Customer对象中，并将其设为外键

有关详细信息，请参阅作为文档

的一部分提供的光滑示例

如何在光滑中创建实体关系？

1 个答案: