Question

我正在使用Play 2.4和Slick 3，是否有可能自动生成ddl脚本，这是演变？

在官方文档中我发现了一些脚本，但是我应该把它放在play框架中？ http://slick.typesafe.com/doc/3.1.0/schemas.html

您是否知道任何用于管理代码中的演进而不编写纯SQL的库？

Answer 1

我使用PostgresDriver做了一些解决方法，我创建了模块，将DDL打印到文件。每次代码更改后，我只需要替换1.sql或稍后修改下一个进化脚本：

ComputersDatabaseModule.scala

package bootstrap

import com.google.inject.AbstractModule
import play.api.{Mode, Play}

class ComputersDatabaseModule extends AbstractModule {

  protected def configure() = {
    bind(classOf[CreateDDL]).asEagerSingleton()
    bind(classOf[InitialData]).asEagerSingleton()
  }
}

CreateDDL.scala

package bootstrap

import java.io.PrintWriter
import javax.inject.Inject

import dao.{CompaniesMapping, ComputersMapping}
import play.api.db.slick.{HasDatabaseConfigProvider, DatabaseConfigProvider}
import slick.driver.JdbcProfile


/**
  * Creates DDL script
  */
private[bootstrap] class CreateDDL @Inject()(protected val dbConfigProvider: DatabaseConfigProvider) extends HasDatabaseConfigProvider[JdbcProfile] with
  ComputersMapping with CompaniesMapping {

  def createDDLScript() = {
    import slick.driver.PostgresDriver.api._

    val allSchemas = companies.schema ++ computers.schema

    val writer = new PrintWriter("target/migration_ddl.sql")
    writer.write("# --- !Ups\n\n")
    allSchemas.createStatements.foreach { s => writer.write(s + ";\n") }

    writer.write("\n\n# --- !Downs\n\n")
    allSchemas.dropStatements.foreach { s => writer.write(s + ";\n") }

    writer.close()
  }

  createDDLScript()
}

ComputersDAO.scala

package dao

import java.util.Date
import javax.inject.{Inject, Singleton}
import models.{Company, Computer, Page}
import play.api.db.slick.{DatabaseConfigProvider, HasDatabaseConfigProvider}
import play.api.libs.concurrent.Execution.Implicits.defaultContext
import slick.driver.JdbcProfile

import scala.concurrent.Future

trait ComputersMapping { self: HasDatabaseConfigProvider[JdbcProfile] =>
  import driver.api._

  class Computers(tag: Tag) extends Table[Computer](tag, "COMPUTER") {

    implicit val dateColumnType = MappedColumnType.base[Date, Long](d => d.getTime, d => new Date(d))

    def id = column[Long]("ID", O.PrimaryKey, O.AutoInc)
    def name = column[String]("NAME")
    def introduced = column[Option[Date]]("INTRODUCED")
    def discontinued = column[Option[Date]]("DISCONTINUED")
    def companyId = column[Option[Long]]("COMPANY_ID")

    def * = (id.?, name, introduced, discontinued, companyId) <> (Computer.tupled, Computer.unapply)
  }

  val computers = TableQuery[Computers]
}

@Singleton()
class ComputersDAO @Inject() (protected val dbConfigProvider: DatabaseConfigProvider) extends CompaniesMapping with ComputersMapping
  with HasDatabaseConfigProvider[JdbcProfile] {
  import driver.api._

  /** Retrieve a computer from the id. */
  def findById(id: Long): Future[Option[Computer]] =
    db.run(computers.filter(_.id === id).result.headOption)

  /** Count all computers. */
  def count(): Future[Int] = {
    // this should be changed to
    // db.run(computers.length.result)
    // when https://github.com/slick/slick/issues/1237 is fixed
    db.run(computers.map(_.id).length.result)
  }
  /** Count computers with a filter. */
  def count(filter: String): Future[Int] = {
    db.run(computers.filter { computer => computer.name.toLowerCase like filter.toLowerCase }.length.result)
  }

  /** Return a page of (Computer,Company) */
  def list(page: Int = 0, pageSize: Int = 10, orderBy: Int = 1, filter: String = "%"): Future[Page[(Computer, Company)]] = {

    val offset = pageSize * page
    val query =
      (for {
        (computer, company) <- computers joinLeft companies on (_.companyId === _.id)
        if computer.name.toLowerCase like filter.toLowerCase
      } yield (computer, company.map(_.id), company.map(_.name)))
        .drop(offset)
        .take(pageSize)

    for {
      totalRows <- count(filter)
      list = query.result.map { rows => rows.collect { case (computer, id, Some(name)) => (computer, Company(id, name)) } }
      result <- db.run(list)
    } yield Page(result, page, offset, totalRows)
  }

  /** Insert a new computer. */
  def insert(computer: Computer): Future[Unit] =
    db.run(computers += computer).map(_ => ())

  /** Insert new computers. */
  def insert(computers: Seq[Computer]): Future[Unit] =
    db.run(this.computers ++= computers).map(_ => ())

  /** Update a computer. */
  def update(id: Long, computer: Computer): Future[Unit] = {
    val computerToUpdate: Computer = computer.copy(Some(id))
    db.run(computers.filter(_.id === id).update(computerToUpdate)).map(_ => ())
  }

  /** Delete a computer. */
  def delete(id: Long): Future[Unit] =
    db.run(computers.filter(_.id === id).delete).map(_ => ())

}

添加配置（ application.config ）：

play.modules.enabled += "bootstrap.ComputersDatabaseModule"

Answer 2

使用Play 2.4及更新版本，光滑的插件不再创建演变。为此，我在开发模式中添加了一个页面，它始终显示浏览器中所有演进的最新版本。此方法与模块系统中即将发生的所有更改兼容，因为它不使用任何模块。使用依赖注入，它完全使用您在 application.conf 文件中配置的Slick数据库驱动程序

我在 config / routes 中添加了以下行：

GET /evolutions.sql                      controllers.SchemaEvolutionsController.evolutions

然后我创建了一个控制器（ app / controllers / SchemaEvolutionsController.scala ）

package controllers

import com.google.inject.Inject
import dao.CatDao
import models.HasSchemaDescription
import models.HasSchemaDescription.SqlSchemaDescription
import play.api.Environment
import play.api.mvc.{Action, Controller}
import play.api.Mode

class SchemaEvolutionsController @Inject() (environment: Environment, catDao : CatDao) extends Controller {

  def allSchemas : Seq[HasSchemaDescription] = List(catDao) // List all schemas here

  def descriptionsForAllSchemas : Seq[SqlSchemaDescription] = allSchemas.map(_.schemaDescription)

  def evolutions = Action {
    environment.mode match {
      case Mode.Prod => NotFound
      case _ => Ok(views.txt.evolutions(descriptionsForAllSchemas)).withHeaders(CONTENT_TYPE -> "text/plain")
    }
  }
}

对于这个控制器，当然有相应的视图（ views / evolutions.scala.txt ）

@import models.HasSchemaDescription.SqlSchemaDescription
@(schemaDescriptions : Seq[SqlSchemaDescription])

# Get the newest version of this evolutions script on the address
# http://localhost:9000@(controllers.routes.SchemaEvolutionsController.evolutions)
# when the server runs in development mode


# --- !Ups

@for(
    schemaDescription <- schemaDescriptions;
    statement <- schemaDescription.createStatements) {
@(statement.replaceAll(";",";;"));
}

# --- !Downs

@for(
    schemaDescription <- schemaDescriptions;
    statement <- schemaDescription.dropStatements) {
@(statement.replaceAll(";",";;"));
}

对于DAO对象，我添加了一个共同的特征来获取模式描述（ app / models / HasSchemaDescription ）：

package models

import models.HasSchemaDescription.SqlSchemaDescription

trait HasSchemaDescription {
  def schemaDescription: SqlSchemaDescription
}

object HasSchemaDescription {
  type SqlSchemaDescription = slick.profile.SqlProfile#SchemaDescription
}

现在对于每个DAO对象，我必须实现特性并将DAO添加到 SchemaEvolutionsController 。

例如，用于服务cat对象的DAO：

class CatDao @Inject()(protected val dbConfigProvider: DatabaseConfigProvider)
  extends HasDatabaseConfigProvider[JdbcProfile] with HasSchemaDescription {
  import driver.api._

  private val Cats = TableQuery[CatsTable]

  def schemaDescription : SqlSchemaDescription = Cats.schema

  def findById(id : Int) : Future[Option[Cat]] =  db.run(Cats.filter(_.id === id).result.headOption)

  private class CatsTable(tag: Tag) extends Table[Cat](tag, "CAT") {

    def id = column[Int]("ID", O.PrimaryKey, O.AutoInc)
    def name = column[String]("NAME")
    def color = column[String]("COLOR")
    def age = column[Option[Int]]("AGE")

    def * = (id, name, color, age) <> (Cat.tupled, Cat.unapply _)
  }
}

通过此示例，您可以在http://localhost:9000/evolutions.sql

上获得以下结果

# Get the newest version of this evolutions script on the address
# http://localhost:9000/evolutions.sql
# when the server runs in development mode


# --- !Ups


create table `CAT` (`ID` INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY,`NAME` TEXT NOT NULL,`COLOR` TEXT NOT NULL,`AGE` INTEGER);


# --- !Downs


drop table `CAT`;

播放框架和Slick自动数据库创建

2 个答案: