CODEWITHSUNDEEP
postgresqlscalablobslickbytea
src091
src091

Reputation: 2847

How do I represent postgres `bytea` type in slick 2.0.1?

In slick's documentation it's said that java.sql.Blob is one of types supported out of the box and I'm attempting to use it to represent bytea column. But the following code gives me an error:

import scala.slick.driver.PostgresDriver.simple._
import java.sql.{ Timestamp, Blob }

case class Test(id: Int, last_updated: Timestamp, data: Blob)

class Tests(tag: Tag) extends Table[Test](tag, "tests") {
  def data = column[Blob]("data")
  def last_updated = column[Timestamp]("last_updated")
  def id = column[Int]("id", O.PrimaryKey)
  def * = (id, last_updated, data)
}

The error message is: 

Multiple markers at this line
    - No matching Shape found. Slick does not know how to map the given types. Possible causes: T in Table[T] does not match your * projection. Or you use an unsupported 
     type in a Query (e.g. scala List). Required level: scala.slick.lifted.ShapeLevel.Flat Source type: (scala.slick.lifted.Column[Int], scala.slick.lifted.Column[java.sql.Timestamp], 
     scala.slick.lifted.Column[java.sql.Blob]) Unpacked type: utils.Test Packed type: Any
    - implements scala.slick.lifted.AbstractTable.$times
    - type mismatch; found : (scala.slick.lifted.Column[Int], scala.slick.lifted.Column[java.sql.Timestamp], scala.slick.lifted.Column[java.sql.Blob]) required: 
     scala.slick.lifted.ProvenShape[utils.Test]
    - type mismatch; found : (scala.slick.lifted.Column[Int], scala.slick.lifted.Column[java.sql.Timestamp], scala.slick.lifted.Column[java.sql.Blob]) required: 
     scala.slick.lifted.ProvenShape[utils.Test]

What is going on and how can I correctly represent bytea in slick?

Upvotes: 2

Views: 1766

Answers (1)

szeiger
szeiger

Reputation: 1406

The problem is not related to Blob support. As the error message suggests as the most common reason, "T in Table[T] does not match your * projection". It should be def * = (id, last_updated, data) <> (Test.tupled, Test.unapply _).

Note that this will still not work for bytea. Slick's PostgreSQL driver maps Blob to the blob type from PotgreSQL's "lo" extension. You need to use Array[Byte] for bytea.

Upvotes: 7

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