Cutting off DateTime precision?

Hi, I haven’t been able to verify that this is a SqlHydra issue and not a SqlKata issue, but I’m having some DateTimes getting truncated to the second in my queries.
I’ve created a query expression to log a select query when executing it:

let private stringifyQuery (query:SqlKata.Query) =
    let compiler = SqlKata.Compilers.SqlServerCompiler()
    let sql = compiler.Compile(query)
    let bindings = 
      String.concat "; " 
        [ 
          for KeyValue (k, v) in sql.NamedBindings -> 
            match v with 
            | :? DateTime as d -> sprintf "(%A: %s)" k (d.ToString("yyyy-MM-dd hh:mm:ss.fffffff"))
            | _ -> sprintf "(%A: %A)" k v
        ]
    sprintf "'%s' with parameters '%s'" sql.Sql bindings

type LoggingSelectBuilder<'a, 'b, 'c when 'c :> Common.DbDataReader> (reader : ('c -> unit -> 'a), ct:ContextType) = 
  inherit SelectAsyncBuilder<'a, 'b, 'c>(reader, ct)

  member this.Run(state: QuerySource<'a, SqlKata.Query>) =
    printfn "%s" <| stringifyQuery state.Query
    base.Run(state)
    
let loggingSelect reader connStr = 
  LoggingSelectBuilder(reader, (ContextType.Create (openContext connStr)))

I have a query like:

  let! myCount = 
    loggingSelect MyDB.HydraReader.Read connStr {
      for record in table<MyDB.dbo.MyTable> do
      where (record.entry_timestamp > ts)
      select (minBy record.entry_timestamp)
    } 
    |>> Array.ofSeq
    |>> Array.head

  printfn "results in: %s" (myCount.ToString("yyyy-MM-dd hh:mm:ss.fffffff"))

which outputs:

'SELECT MIN([MyTable].[entry_timestamp]) FROM [MyTable] WHERE ([MyTable].[entry_timestamp] > @p0)' with parameters '("@p0": 2022-07-15 09:40:42.6078010)'

results in: 2022-07-15 09:40:42.6077917

it seems like I have to add a full second to the timestamp in the query to get the results I want.
Do you think this is a SqlKata issue or a SqlHydra issue? Do you have any recommendations for how to debug this? A SqlKata developer claims that SqlKata sends raw DateTime parameters to the DB server unaltered in this issue, and is correct as far as what I can tell from the SqlKata source. But I also can’t see in SqlHydra source anywhere that the truncation would be happening.

[JordanMarr]

No worries, that stuff is hard. I personally never use the devcontainer setup, mostly because I prefer using Visual Studio over vscode. So I just do docker-compose up instead and then use VS.

As for modifying the table, maybe you can append the new table create script to the install.sql file and then re-run the script?

At least that’s what we did for the test tables created in the postgres install.sql file.

[JordanMarr]

Nice work on the testing! It looks as though this issue can be resolved in SqlHydra. A similar mechanism is already in place for SqlHydra.Npgsql jsonb types that we can use here. I think it should be pretty straight forward change.