在Play Slick中分配动态注入的数据库名称 [英] Assign dynamically injected database name in Play Slick

问题描述

我有以下Play Slick DAO课程.请注意，数据库配置是常量control0001. DAO具有readUser函数，该函数根据用户ID读取用户:

I have the following Play Slick DAO class. Note that the database configuration is a constant control0001. The DAO has a function readUser that reads a user based on its user id:

class UsersDAO @Inject()(@NamedDatabase("control0001") 
    protected val dbConfigProvider: DatabaseConfigProvider) 
                  extends HasDatabaseConfigProvider[JdbcProfile] {

   import driver.api._

   def readUser (userid: String) = {
      val users = TableQuery[UserDB]
      val action = users.filter(_.userid === userid).result
      val future = db.run(action.asTry)
      future.map{
        case Success(s) => 
          if (s.length>0)
            Some(s(0))
          else
            None
        case Failure(e) => throw new Exception ("Failure in readUser: " + e.getMessage)
      }
   }
}

除了在@NamedDatabase("control0001")中没有常量之外，我需要数据库是可变的.在应用程序中，我在application.conf中配置了多个数据库(control0001，control002等).根据变量值，我需要确定要在DAO中使用的数据库.所有数据库都是相似的，并且具有相同的表(每个数据库中的数据都不同).

Instead of having a constant in @NamedDatabase("control0001"), I need the database to be variable. In the application, I have multiple databases (control0001, control002 and so on) configured in application.conf. Depending on a variable value, I need to determine the database to be used in the DAO. All the databases are similar and have the same tables (the data in each database differs).

以下Play类调用DAO函数，但首先需要确定要注入的数据库名称:

The following Play class calls the DAO function, but first it needs to determine the database name to be injected:

class TestSlick  @Inject()(dao: UsersDAO) extends Controller  {

  def test(someCode: Int, userId: String) = Action { request =>

    val databaseName = if (someCode == 1) "control0001" else "control0002"

    // Run the method in UsersDAO accessing the database set by databaseName

    val future = dao.readUser(userId) 
    future.map { result =>
      result match {
        case Some(user) => Ok(user.firstName)
        case _ => Ok("user not found")
      }
    }
  }        
}

如何在Play Slick中实现?

How can this be achieved in Play Slick?

推荐答案

您可以尝试初始化覆盖默认配置的slick db对象:

You can try to initialize slick db object overriding default config:

val db = Database.forURL("jdbc:mysql://localhost/" + databaseName, driver="org.h2.Driver")

更多信息，请参见slick docs http://slick.lightbend.com/doc/3.0.0/database.html

more information in slick docs http://slick.lightbend.com/doc/3.0.0/database.html

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