Apply Slick filter depending on condition

Question

I have the following Slick function that has a filter (d.sk < sk):

   def func1(sk: Int) = {
      val date2 = TableQuery[DatesDB] 
      val action = date2.filter( d => (d.sk < sk)).result
      val future = db.run(action.asTry)
      future.map {
        case Success(s) => 
          if (s.length > 0)
            Some(s(0))
          else
            None
        case Failure(e) => throw new Exception("Failure")
      }
   }

What I need is to add a feature to this function that depending on a condition X the filter should be either the existent one or (d.sk <= sk). Since filters are not variables I don't know how to achieve this, and I prefer not to rewrite the filters or actions. Any ideas?

SergGr SergGr · Accepted Answer · 2017-05-04T21:03:14

Cyrille's link seems to be about a bit different case but that approach might be extended to cover your case as well. Still if this is just one place, what's wrong with good old if:

val date2 = TableQuery[DatesDB] 
val query = if (condition) date2.filter(d => (d.sk < sk)) else date2.filter(d => (d.sk <= sk))
val action = query.result

Another idea

val date2 = TableQuery[DatesDB] 
val action = date2.filter(d => ((LiteralColumn(condition) && (d.sk < sk)) || (LiteralColumn(!condition) && (d.sk <= sk))).result

Apply Slick filter depending on condition

1 Answers