Parsing error and single-table inheritance

[ddunlea]

I have a fairly complicated query that joins across several tables, one of which uses single-table inheritance.

@Selection
public struct FlattendRecords: Equatable, Identifiable, Sendable {
  public let id: Int
  public let first: First
  public let second: Second
  public let third: Third
  public let quantity: Decimal
  
  public static func all() -> Select<FlattendRecords.Selection.QueryValue, SecondThirdMapping, (Third, Second, First)> {
    SecondThirdMapping
      .join(Third.all) { mapping, third in
        mapping.thirdId.eq(third.id)
      }
      .join(Second.all) { mapping, third, second in
        mapping.secondId.eq(second.id)
      }
      .join(First.all) { mapping, third, second, first in
        second.firstId.eq(first.id)
      }
      .select { mapping, third, second, first in
        FlattendRecords.Columns(id: mapping.id, first: first, second: second, third: third, quantity: mapping.quantity)
      }
  }
}

When that table contains data from one of the two sub-types, it is all fine. When it contains data from the other sub-type, I get a parsing error.

✘ Test failingExample() recorded an issue at DbLibraryTests.swift:60:2: Caught error: Error Domain=NSCocoaErrorDomain Code=2048 "Cannot parse 2. String should adhere to the preferred format of the locale, such as 2025-10-29 16:09:56." UserInfo={NSDebugDescription=Cannot parse 2. String should adhere to the preferred format of the locale, such as 2025-10-29 16:09:56.}

I have an example project with a passing and failing test, both of which execute the same query, just with different data in the table. The test is here

I suspect I may be using single-table inheritance incorrectly. Any pointers would be very welcome

[stephencelis]

@ddunlea This is actually a bug in decoding enums! This PR should fix it: #220

Thanks for the report!

[ddunlea]

Fantastic! Thanks so much for the quick turnaround!