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indigostar-kr/PatchActionExtensionMethodsSupport.scala

Created February 2, 2017 12:36
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Implement partial update of Product in Slick
Raw
PatchActionExtensionMethodsSupport.scala
package slick.extensions
import slick.ast._
import slick.dbio.{ Effect, NoStream }
import slick.driver.JdbcDriver
import slick.jdbc._
import slick.lifted._
import slick.relational.{ CompiledMapping, ProductResultConverter, ResultConverter, TypeMappingResultConverter }
import slick.util.{ ProductWrapper, SQLBuilder }
import scala.language.{ existentials, higherKinds, implicitConversions }
trait PatchActionExtensionMethodsSupport { driver: JdbcDriver =>
trait PatchActionImplicits {
implicit def queryPatchActionExtensionMethods[U <: Product, C[_]](
q: Query[_, U, C]
): PatchActionExtensionMethodsImpl[U] =
createPatchActionExtensionMethods(updateCompiler.run(q.toNode).tree, ())
}
///////////////////////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////// Patch Actions
///////////////////////////////////////////////////////////////////////////////////////////////
type PatchActionExtensionMethods[T <: Product] = PatchActionExtensionMethodsImpl[T]
def createPatchActionExtensionMethods[T <: Product](tree: Node, param: Any): PatchActionExtensionMethods[T] =
new PatchActionExtensionMethodsImpl[T](tree, param)
class PatchActionExtensionMethodsImpl[T <: Product](tree: Node, param: Any) {
protected[this] val ResultSetMapping(_, CompiledStatement(_, sres: SQLBuilder.Result, _),
CompiledMapping(_converter, _)) = tree
protected[this] val converter = _converter.asInstanceOf[ResultConverter[JdbcResultConverterDomain, Product]]
protected[this] val TypeMappingResultConverter(childConverter, toBase, toMapped) = converter
protected[this] val ProductResultConverter(elementConverters @ _ *) =
childConverter.asInstanceOf[ResultConverter[JdbcResultConverterDomain, Product]]
private[this] val updateQuerySplitRegExp = """(.*)(?<=set )((?:(?= where)|.)+)(.*)?""".r
private[this] val updateQuerySetterRegExp = """[^\s]+\s*=\s*\?""".r
/** An Action that updates the data selected by this query. */
def patch(value: T): DriverAction[Int, NoStream, Effect.Write] = {
val (seq, converters) = value.productIterator.zipWithIndex.toIndexedSeq
.zip(elementConverters)
.filter {
case ((Some(_), _), _) => true
case ((None, _), _) => false
case ((null, _), _) => false
case ((_, _), _) => true
}
.unzip
val (products, indexes) = seq.unzip
val newConverters = converters.zipWithIndex
.map(c => (c._1, c._2 + 1))
.map {
case (c: BaseResultConverter[_], idx) => new BaseResultConverter(c.ti, c.name, idx)
case (c: OptionResultConverter[_], idx) => new OptionResultConverter(c.ti, idx)
case (c: DefaultingResultConverter[_], idx) => new DefaultingResultConverter(c.ti, c.default, idx)
case (c: IsDefinedResultConverter[_], idx) => new IsDefinedResultConverter(c.ti, idx)
}
val productResultConverter =
ProductResultConverter(newConverters: _*).asInstanceOf[ResultConverter[JdbcResultConverterDomain, Any]]
val newConverter = TypeMappingResultConverter(productResultConverter, (p: Product) => p, (a: Any) => toMapped(a))
val newValue: Product = new ProductWrapper(products)
val newSql = sres.sql match {
case updateQuerySplitRegExp(prefix, setter, suffix) =>
val buffer = StringBuilder.newBuilder
buffer.append(prefix)
buffer.append(
updateQuerySetterRegExp
.findAllIn(setter)
.zipWithIndex
.filter(s => indexes.contains(s._2))
.map(_._1)
.mkString(", ")
)
buffer.append(suffix)
buffer.toString()
}
new SimpleJdbcDriverAction[Int]("patch", Vector(newSql)) {
def run(ctx: Backend#Context, sql: Vector[String]): Int =
ctx.session.withPreparedStatement(sql.head) { st =>
st.clearParameters
newConverter.set(newValue, st)
sres.setter(st, newConverter.width + 1, param)
st.executeUpdate
}
}
}
}
}
@indigostar-kr
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indigostar-kr commented Feb 2, 2017

Example

// Model
case class User(
  id: Option[Int] = None,
  name: Option[String] = None,
  username: Option[String] = None,
  password: Option[String] = None
)

// Table
class Users(tag: Tag) extends Table[User](tag, "users") {
  def id = column[Int]("id", O.PrimaryKey, O.AutoInc)
  def name = column[String]("name")
  def username = column[String]("username")
  def password = column[String]("password")
  override def * = (id.?, name.?, username.?, password.?) <>(User.tupled, User.unapply)
}

// TableQuery
object Users extends TableQuery(new Users(_))

// CustomDriver 
trait CustomDriver extends PostgresDriver with PatchActionExtensionMethodsSupport {
  override val api: API = new API {}
  trait API extends super.API  with PatchActionImplicits
}

// Insert
Users += User(Some(1), Some("Test"), Some("test"), Some("1234"))

// User patch
Users.filter(_.id === 1).patch(User(name = Some("Change Name"), username = Some("")))

@rgladwell
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rgladwell commented Feb 2, 2017

Looks like the moderators deleted your answer on Stackoverflow:

http://stackoverflow.com/questions/30848004/how-do-you-run-a-patch-partial-database-update-in-scala-slick/42002806#42002806

You might want to re-post with the above code pasted there?

@indigostar-kr
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indigostar-kr commented Feb 13, 2017

Removal of Stackoverflow has been removed because it did not provide details.

You can copy and re-post.

@indigostar-kr
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indigostar-kr commented Feb 13, 2017

Stackoverflow duplicate posts: http://stackoverflow.com/a/42004236/7505973

@anqit
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anqit commented Sep 9, 2021

This doesn't seem to work for slick 3.3.3, as it seems SimpleJdbcDriverAction no longer exists. Any hints on updating this?

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