How to map Map[String, String] to (String, String) in slick 3.2.0

I am trying to update the hstore field in my Postgres table. It throws an error

Error:(468, 13) 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,
 you use an unsupported type in a Query (e.g. scala List),
 or you forgot to import a driver api into scope.
  Required level: slick.lifted.FlatShapeLevel
     Source type: slick.lifted.Rep[Option[scala.collection.immutable.Map[String,String]]]
   Unpacked type: T
     Packed type: G
        .map(_.additionalInfo).update(Some(info.additionalInfo))

I have added hstore implicit as well

trait MyPostgresDriver extends ExPostgresProfile with PgHStoreSupport {

  override val api = MyAPI

  // Add back `capabilities.insertOrUpdate` to enable native `upsert` support; for postgres 9.5+
  override protected def computeCapabilities: Set[Capability] =
    super.computeCapabilities + JdbcProfile.capabilities.insertOrUpdate


  object MyAPI extends API with HStoreImplicits

}

After browsing I found to create a custom mapping for such scenarios.

implicit val stringMapper = MappedColumnType.base[Map[String, String], (String, String)](
    list => (list.keys.toString(), list.values.toString()),
    string => Map(string._1 -> string._2)
  )

But above custom mapping is not correct. I found this blog But it Implicits is not there in version 3.x

Any help will be appreciated.

Solution

As per the error, slick implicit is missing which help you to use Map[String, String] as PgHStore. You need to add (implicit a: JdbcType[Map[String, String]]) in the scope of your code block. which is I guess provided by HStoreImplicits Or PgHStoreSupport.