Not Implemented Exception While Using SRTP

Issue Calling code similar to below will result in a Not Implemented Exception. Area of code is found here for the ‘isIn’ function https://github.com/Dzoukr/Dapper.FSharp/blob/master/src/Dapper.FSharp/MSSQL/LinqExpressionVisitors.fs#L218

Use Case I have a quite a few similar queries where I need to check for existence in various tables and other minute validations. If I am thinking about this correctly, I think adding support for SRTP would provide benefit in being able to create re-usable queries so I don’t have to create a new query for each table.

#r "nuget: Dapper.FSharp"
open Dapper.FSharp
open Dapper.FSharp.MSSQL
open System.Data

[<CLIMutable>]
type Person = 
    { 
        Id : int 
    }

[<CLIMutable>]
type Dog = 
    { 
        Id : int 
    }

let people = table'<Person> "People"
let dogs = table'<Dog> "Dogs"

let inline getIds<'T 
    when 'T: (member Id : int)> 
    (ids : int list) 
    (querySource : QuerySource<'T>) 
    (conn : IDbConnection) 
    = async {
    // This is required in order to use SRTP w/ the query builder
    let getId (item : 'T) = item.Id
    
    let query = select {
        for row in querySource do
            where (isIn (getId row) ids)
    }

    return! conn.SelectAsync<'T>(query) |> Async.AwaitTask
}

[1eyewonder]

Yep, that makes sense. Thank you so much for your help!

[JordanMarr]

Personally, I will always opt for an extra type or function over SRTP for simplicity. I think using an anonymous record would be the better play in this case:

let queryByIds<'T> (ids: int list) tableName (conn: IDbConnection) = 
  async {
    let query = 
      select {
          for row in table'<{| Id: int |}> tableName do
          where (isIn row.Id ids)
      }

    return! conn.SelectAsync<'T>(query) |> Async.AwaitTask
  }

let! dogs = queryByIds<Dog> [1;2;3] "Dogs" conn