gistfile1.txt

// optionally filter on a column with a supplied predicate
case class MaybeFilter[X, Y](val query: scala.slick.lifted.Query[X, Y]) {
  def filter[T](data: Option[T])(f: T => X => scala.slick.lifted.Column[Boolean]) = {
    data.map(v => MaybeFilter(query.filter(f(v)))).getOrElse(this)
  }
}

// example use case
def find(id: Option[Int], createdMin: Option[Date], createdMax: Option[Date], modifiedMin: Option[Date], modifiedMax: Option[Date]) = {

val query = MaybeFilter(Query(this))
.filter(id)(v => d => d.id === v)
.filter(createdMin)(v => d => d.created >= v)
.filter(createdMax)(v => d => d.created <= v)
.filter(modifiedMin)(v => d => d.modified >= v)
.filter(modifiedMax)(v => d => d.modified <= v)           
.query
      
query.list

}