In Mapper's having String as a primary Key, why is the MappedStringIndex not shown in the list of all fields that are obtained via the Mapper's allFields method
My Mapper goes like this ...
class DummyMapper extends KeyedMapper[String,DummyMapper] {
def getSingleton = DummyMapper
def primaryKeyField = dummyCode
object dummyCode extends MappedStringIndex(this,5)
{
override def writePermission_? = true
override def dbAutogenerated_? = false
override def dbNotNull_? = true
override def dbColumnName="dummy_code"
}
.....
I even tried it including in the fieldOrder. Still the result was same, it din't showed up in DummyMapper.allFields list
primarykey fields ( of any data-type ) are not included in the list returned by allFileds method of the Mapper.
You can prepend the field separately if you want
something like
var myMapperPrimaryKey=DummyMapper.primaryKeyField
var fieldList=DummyMapper.allFields.toBuffer[BaseField]
fieldList.prepend(myMapperPrimaryKey)
// Now fieldList is having the primaryKey along with other fields.
Related
I need to write two functions to get the output format and the output index for file conversion. As part of this, I wrote a TransformSettings class for these methods and set the default value. And in the transformer class, I created a new object of TransformSettings class to get the default values for each job run. Also, I have another class called ParquetTransformer that extends Transformer where I want to change these default values. So I implemented like below.
class TransformSettings{
def getOuputFormat: String = {
"orc"
}
def getOuputIndex(table: AWSGlueDDL.Table): Option[String] = {
table.StorageDescriptor.SerdeInfo.Parameters.get("orc.column.index.access")
}
}
class Transformer{
def getTransformSettings: TransformSettings = {
new TransformSettings
}
def posttransform(table: AWSGlueDDL.Table):Dateframe ={
val indexAccess = getTransformSettings.getOuputIndex(table: AWSGlueDDL.Table)
........
}
}
class ParquetTransformer extends Transformer{
override def getTransformSettings: TransformSettings = {
val transformSettings = new TransformSettings {
override def getOuputFormat: String = {
"parquet"
}
override def getOuputIndex(table: AWSGlueDDL.Table): Option[String] = {
table.StorageDescriptor.SerdeInfo.Parameters.get("parquet.column.index.access")
}
}
}
}
Is there a way to avoid creating a brand new object of TransformSettings in Transfomer class every time this is called?
Also is there a way to rewrite the code using Scala value class?
As #Dima proposed in the comments try to make TransformSettings a field / constructor parameter (a val) in the class Transformer and instantiate them outside
class TransformSettings{
def getOuputFormat: String = {
"orc"
}
def getOuputIndex(table: AWSGlueDDL.Table): Option[String] = {
table.StorageDescriptor.SerdeInfo.Parameters.get("orc.column.index.access")
}
}
class Transformer(val transformSettings: TransformSettings) {
def posttransform(table: AWSGlueDDL.Table): DataFrame ={
val indexAccess = transformSettings.getOuputIndex(table: AWSGlueDDL.Table)
???
}
}
val parquetTransformSettings = new TransformSettings {
override def getOuputFormat: String = {
"parquet"
}
override def getOuputIndex(table: AWSGlueDDL.Table): Option[String] = {
table.StorageDescriptor.SerdeInfo.Parameters.get("parquet.column.index.access")
}
}
class ParquetTransformer extends Transformer(parquetTransformSettings)
You don't seem to need value classes (... extends AnyVal) now. They are more about unboxing, not about life-cycle management. TransformSettings and Transformer can't be value classes because they are not final (you're extending them in class ParquetTransformer extends Transformer... and new TransformSettings { ... }). By the way, value classes have many limatations
https://failex.blogspot.com/2017/04/the-high-cost-of-anyval-subclasses.html
https://github.com/scala/bug/issues/12271
Besides value classes, there are scala-newtype library in Scala 2 and opaque types in Scala 3.
I'm writing a CRUD app using Slick, and I want my update queries to only update a specific set of columns and I use .map().update() for that.
I have a function that returns a tuple of fields that can be updated in my table definition (def writableFields). And I have a funciton that returns a tuple of values to write there extracted from a case class.
It works fine, but it's annoying to create a repo and write the whole update function for every table. I want to create a generic form of this function, and make my table and it's companion object to extend some trait. But I cannot come up with correct type definitions.
Slick expects output of map() to be somehow compatible with the output of update. And I don't know how to make a generic type for tuples.
Is it even possible to accomplish? Or is there an alternative way to limit code duplication? Ideally I want to avoid writing Repos at all and just either instantiate a generic class or call a generic method.
object ProjectsRepo extends BaseRepository[Projects, Project] {
protected val query = lifted.TableQuery[Projects]
def update(id: Long, c: Project): Future[Option[Project]] = {
val q = filterByIdQuery(id).map(_.writableFields)
.update(Projects.mapFormToTable(c))
(db run q).flatMap(
affected =>
if (affected > 0) {
findOneById(id)
} else {
Future(None)
}
)
}
}
class Projects(tag: Tag) extends Table[Project](tag, "projects") with IdentifiableTable[Long] {
val id = column[Long]("id", O.PrimaryKey, O.AutoInc)
val title = column[String]("title")
val slug = column[String]("slug")
val created_at = column[Timestamp]("created_at")
val updated_at = column[Timestamp]("updated_at")
def writableFields =
(
title,
slug
)
def readableFields =
(
id,
created_at,
updated_at
)
def allFields = writableFields ++ readableFields // shapeless
def * = allFields <> (Projects.mapFromTable, (_: Project) => None)
}
object Projects {
def mapFormToTable(c: Project): FormFields =
(
c.title,
c.slug
)
}
I have a custom column in my Slick as follow:
class PgACL(tag: Tag) extends Table[ACL](tag, Some(schemaName), "ACL") {
def id = column[UUID]("ID", O.PrimaryKey)
def resourceSpec = column[ResourceSpec]("RESOURCE_SPEC")
def * = (id, resourceSpec) <>(ACL.tupled, ACL.unapply)
}
and the custom class:
case class ResourceSpec (val resourceType: String, val resourceId: String)
And I map them like this:
implicit val ResourceSpecMapper = MappedColumnType.base[ResourceSpec, String](
resourceSpec => resourceSpec.resourceSpecStr,
str => ResourceSpec.fromString(str)
)
I am trying to have a query which filter based on a property of the custom column, but I don't know how I can access to it. For example I want to have:
TableQuery[PgACL].filter(x => x.resourceSpec.resourceType === "XYZ")
But x.resourceSpec returns Rep[ResourceSpec] and I don't know how to get its "resourceType" property.
Any help?
I'm new to Slick thus I'm not sure whether the problem caused by incorrect usage of implicits or Slick doesn't allow doing what I'm trying to do.
In short I use Slick-pg extension for JSONB support in Postgres. I also use spray-json to deserialize JSONB fields into case classes.
In order to automagically convert columns into objects I wrote generic implicit JsonColumnType that you can see below. It allows me to have any case class for which I defined json formatter to be converted to jsonb field.
On the other hand I want to have alias of JsValue type for the same column so that I can use JSONB-operators.
import com.github.tminglei.slickpg._
import com.github.tminglei.slickpg.json.PgJsonExtensions
import org.bson.types.ObjectId
import slick.ast.BaseTypedType
import slick.jdbc.JdbcType
import spray.json.{JsValue, RootJsonWriter, RootJsonReader}
import scala.reflect.ClassTag
trait MyPostgresDriver extends ExPostgresDriver with PgArraySupport with PgDate2Support with PgRangeSupport with PgHStoreSupport with PgSprayJsonSupport with PgJsonExtensions with PgSearchSupport with PgNetSupport with PgLTreeSupport {
override def pgjson = "jsonb" // jsonb support is in postgres 9.4.0 onward; for 9.3.x use "json"
override val api = MyAPI
private val plainAPI = new API with SprayJsonPlainImplicits
object MyAPI extends API with DateTimeImplicits with JsonImplicits with NetImplicits with LTreeImplicits with RangeImplicits with HStoreImplicits with SearchImplicits with SearchAssistants { //with ArrayImplicits
implicit val ObjectIdColumnType = MappedColumnType.base[ObjectId, Array[Byte]](
{ obj => obj.toByteArray }, { arr => new ObjectId(arr) }
)
implicit def JsonColumnType[T: ClassTag](implicit reader: RootJsonReader[T], writer: RootJsonWriter[T]) = {
val columnType: JdbcType[T] with BaseTypedType[T] = MappedColumnType.base[T, JsValue]({ obj => writer.write(obj) }, { json => reader.read(json) })
columnType
}
}
}
object MyPostgresDriver extends MyPostgresDriver
Here is how my table is defined (minimized version)
case class Article(id : ObjectId, ids : Ids)
case class Ids(doi: Option[String], pmid: Option[Long])
class ArticleRow(tag: Tag) extends Table[Article](tag, "articles") {
def id = column[ObjectId]("id", O.PrimaryKey)
def idsJson = column[JsValue]("ext_ids")
def ids = column[Ids]("ext_ids")
private val fromTuple: ((ObjectId, Ids)) => Article = {
case (id, ids) => Article(id, ids)
}
private val toTuple = (v: Article) => Option((v.id, v.ids))
def * = ProvenShape.proveShapeOf((id, ids) <> (fromTuple, toTuple))(MappedProjection.mappedProjectionShape)
}
private val articles = TableQuery[ArticleRow]
Finally I have function that looks up articles by value of json field
def getArticleByDoi(doi : String): Future[Article] = {
val query = (for (a <- articles if (a.idsJson +>> "doi").asColumnOf[String] === doi) yield a).take(1).result
slickDb.run(query).map { items =>
items.headOption.getOrElse(throw new RuntimeException(s"Article with doi $doi is not found"))
}
}
Sadly I get following exception in runtime
java.lang.ClassCastException: spray.json.JsObject cannot be cast to server.models.db.Ids
The problem is in SpecializedJdbcResultConverter.base where ti.getValue is being called with wrong ti. It should be slick.driver.JdbcTypesComponent$MappedJdbcType but instead it's com.github.tminglei.slickpg.utils.PgCommonJdbcTypes$GenericJdbcType. As result wrong type is passed into my tuple converter.
What makes Slick choose different type for column even though there is explicit definition of projection in table row class ?
Sample project that demonstrates the issue is here.
I have a field that I would like to be read-only and have a default value.
here what I have till now:
object passwd extends MappedString(this, 20)
{
override def defaultValue = "XXX" + Random.alphanumeric.take(12).mkString // some default value
// readOnly = true // Or something similar???
}
I tried overriding toHtml, asHtml, toForm, displayHtml but they all change the view or the label or something else.
I just want the defaultValue to be automatically generated (which works) but the users not to be able to edit that field when create/editing the entity.
Any advice would be very much appreciated
Got it,
Just override _toForm and disable the input element:
import net.liftweb.http.S
override def _toForm =
S.fmapFunc({s: List[String] => this.setFromAny(s)}){name =>
Full(<input disabled='disabled' type='text' id={fieldId} maxlength={maxLen.toString}
name={name}
value={is match {case null => "" case s => s.toString}}/>)}
The trait MappedField defines the methods writePermission_? and readPermission_?:
/**
* Given the current execution state, can the field be written?
*/
def writePermission_? = false
/**
* Given the current execution state, can the field be read?
*/
def readPermission_? = false
So you could just override these with
object passwd extends MappedString(this, 20) {
override def defaultValue = "XXX" + Random.alphanumeric.take(12).mkString // some default value
override writePermission_? = false
override readPermission_? = true
}
Is that what you're looking for?