Adding PGVector Support

[AndrewCatwalk]

Hi, I'm interested in adding PGVector support to my application using ScalaSQL, by combining it with https://github.com/pgvector/pgvector-java

I've set up a type mapper which looks reasonable, and works for 'SELECT' statements:

object PGVector {
  implicit val PgVectorMapper: TypeMapper[PGvector] = new PGVectorType

  class PGVectorType extends TypeMapper[PGvector] {
    def jdbcType = JDBCType.OTHER

    override def get(r: ResultSet, idx: Int): PGvector = {
      r.getObject(idx).asInstanceOf[PGvector]
    }

    override def put(r: PreparedStatement, idx: Int, v: PGvector): Unit =
      r.setObject(idx, v)
  }
}

However, when I try to perform an 'Update' operation, I get the following error:

      db.run(
        PostVectors
          .update(_.postId === id)
          .set(_.gmmeVector := vector)
      )


Found: (vector : com. pgvector. PGvector) Required: scalasql. core. Expr[com. pgvector. PGvector]

I've taken a look at some PRs to scalasql itself to add types (like: https://github.com/com-lihaoyi/scalasql/pull/24/files#diff-2582d86ab940606751cc634979ce1cb049098d0b5cd0754f00ce9be80bedb831) , but nothing I've tried has worked. Any guidance on what might be missing would be greatly appreciated!

[samikrc]

Can you wrap the vector in .set(_.gmmeVector := vector) in an Expr? I have seen a few cases like this, and might be helpful.

[AndrewCatwalk]

Like so?

      db.run(
        PostVectors
          .update(_.postId === id)
          .set(_.gmmeVector := Expr(vector))
      ) 

That introduces a bigger type error:

No given instance of type com. pgvector. PGvector => scalasql. core. SqlStr. Interp was found for parameter conv of method apply in object Expr. 

I found:  
{ def $anonfun(value: com. pgvector. PGvector): scalasql. core. SqlStr. Interp = scalasql. core. SqlStr. Interp. typeInterp[T](value)( scalasql. PostgresDialect. EnumType[T²]) closure($anonfun) }  

But method typeInterp in object Interp does not match type com. 

pgvector. PGvector => scalasql. core. SqlStr. Interp  

where: T is a type variable T² is a type variable with constraint <: Enumeration#Value .

[samikrc]

Yes - like that - or so I thought. Sorry - have been away.
Can you post the progress so far in the discord channel? May be Li or others can chime in.
https://discord.com/channels/632150470000902164/940067748103487558