How does one reuse complex queries with mapping to custom rows for query composition in slick?
Given some complex query with mapping.
case class ComplexQueryResult( someValue: SomeValue / * other values */)
val aComplexQuery =
// many joins resulting in a complex query with a map
// to convert the result into something more readable
.map {
case (/* complex touple */) =>
ComplexQueryResult( /* value assignment */) <> ((ComplexQueryResult.apply _).tupled, ComplexQueryResult.unapply)
}
The type of this query will be Query[MappedProjection[ComplexQueryResults, /* other query information */]
What I would like to do is reuse this query in another join, so that I can do:
val composedQuery =
aComplexQuery
.join(someOtherQuery)
.on { case(complexQueryResult, /* result of someOtherQuery */) =>
// << here lies the source of my confusion
}
Unfortunately there seems to be no way to access the elements of a mapped projection to perform another join. How do I join such queries?
