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Correct use of the stain filter

I am using slick to access the database. I want to query like this:

case class Coupon(couponId: Long, shopId: String)

class Coupons(tag: Tag) extends Table[Coupon](tag, "coupons"){

  def couponId = column[Long]("coupon_id")

  def shopId = column[String]("shop_id")

  override def * = (couponId, shopId) <> (Coupon.tupled, Coupon.unapply)
}

object Coupons extends TableQuery(new Coupons(_)){

  def findCouponBy(couponId: Long, shopId: Option[String]) = {

    val s = DB.createSession()
    try {
       val q = for {
           coupon <- this.filter(c => c.couponId === couponId && 
                shopId.map(s => c.shopId === s).getOrElse(true)
        } yield coupon
      s.database.run(q.result)
    } finally s.close
  }
}

I thought it might work. However, the compiler tells me that the error is: (126, -1) Play 2 Compiler: type mismatch; Found: Required: slick.lifted.Rep [?]

The problem is this: shopId.map (s => c.shopId === s) .getOrElse (true)

I am wondering how I can make this work.

I am using slick 3.0.0-RC

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2 answers


Use slick.lifted.LiteralColumn(true)



Scala type constraint

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As mentioned in this answer, you can use the following API starting with Slick version 3.3.0 :



def findCouponBy(couponId: Long, shopId: Option[String]) = {
  val query = 
    this
      .filter(_.couponId === couponId)
      .filterOpt(shopId){ case (table, sid) =>
        table.filter(_.shopId === sid)
      }

  db run query.result
}
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