Slick2 使用笔记(3) 实际应用的一些操作以及其他补充内容

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本文是slick2 笔记1和2的补充 在实际使用下的一些操作

 

使用SourceCodeGenerator生成实体和操作类

这个类没有提供用户名和密码的参数 所以需要自己改写一个

直接根据scala.slick.model.codegen.SourceCodeGenerator改就可以了

一个例子:

package mysql_sourceGen

import scala.slick.{ model => m }
import scala.slick.model.codegen._

class MySQLSourceCodeGenerator(model: m.Model)
  extends AbstractSourceCodeGenerator(model) with OutputHelpers {
  type Table = TableDef
  def Table = new TableDef(_)
  class TableDef(model: m.Table) extends super.TableDef(model) {
    type EntityType = EntityTypeDef
    def EntityType = new EntityType {}
    type PlainSqlMapper = PlainSqlMapperDef
    def PlainSqlMapper = new PlainSqlMapper {}
    type TableClass = TableClassDef
    def TableClass = new TableClass {}
    type TableValue = TableValueDef
    def TableValue = new TableValue {}
    type Column = ColumnDef
    def Column = new Column(_)
    type PrimaryKey = PrimaryKeyDef
    def PrimaryKey = new PrimaryKey(_)
    type ForeignKey = ForeignKeyDef
    def ForeignKey = new ForeignKey(_)
    type Index = IndexDef
    def Index = new Index(_)
  }
}

object MySQLSourceCodeGenerator {
  import scala.slick.driver.JdbcProfile
  import scala.reflect.runtime.currentMirror
  def main(args: Array[String]) = {
    args.toList match {
      case List(slickDriver, jdbcDriver, url, outputFolder, pkg, user, pass) => {
        val driver: JdbcProfile = {
          val module = currentMirror.staticModule(slickDriver)
          val reflectedModule = currentMirror.reflectModule(module)
          val driver = reflectedModule.instance.asInstanceOf[JdbcProfile]
          driver
        }
        driver.simple.Database
          .forURL(url, driver = jdbcDriver, password = pass, user = user)
          .withSession { implicit session =>
            (new SourceCodeGenerator(driver.createModel)).writeToFile(slickDriver, outputFolder, pkg)
          }
      }
      case _ => {
        println("""
Usage: SourceCodeGenerator.main(Array( slickDriver, jdbcDriver, url, outputFolder, pkg ))

slickDriver: Fully qualified name of Slick driver class, e.g. "scala.slick.driver.H2Driver"

jdbcDriver: Fully qualified name of jdbc driver class, e.g. "org.h2.Driver"

url: jdbc url, e.g. "jdbc:postgresql://localhost/test"

outputFolder: Place where the package folder structure should be put

pkg: Scala package the generated code should be places in
            
user: DataBase's username

pass : the user's password
            """.trim)
      }
    }
  }
}

 我起的名字有歧义 这个不只是mysql可以用 所有都可以用 你传入driver的字符串就可以了

 

 

多表以及分页查询的例子：

    SlickDB.database.withSession {
      implicit session =>
        val query = for {
          cid <- Tables.Category.filter(_.name === tag).map(_.id)
          aids <- Tables.ArticleCategory.filter(_.cId === cid).map(_.aId)
          article <- Tables.Article.filter(_.id === aids)
        } yield article
        ((query.length.run-1) /Constants.PageSize +1,
        query.sortBy(_.time desc).drop((page - 1) * Constants.PageSize).take(Constants.PageSize).list)
    }

 从tag表拿出tag得到对应的cid 根据对应的cid找到文章的aid 根据文章的id得到文章

多对多查询有中间表时使用的例子 

后面的分页 按照时间降序 得到第page(从1开始)页的数据

 

 

插入得到id的例子：

val aid =
          (Tables.Article returning Tables.Article.map(_.id)) += article

 类似于postgresql的 returnning