No mapping exists for Guid option

[joelvandiver]

Description

A Guid option is throwing an exception with a query.

Repro steps

1. Table Definition:

   CREATE TABLE MySchema.MyTable (
     Id               uniqueidentifier NOT NULL
   , ObjectId         uniqueidentifier NULL
   , CONSTRAINT PK_MyTable PRIMARY KEY CLUSTERED (Id ASC)
   );

2. Example Script

   
   type DBSchema =
   SqlDataProvider<
           ConnectionStringName = "MyDB",
           DatabaseVendor = Common.DatabaseProviderTypes.MSSQLSERVER,
           UseOptionTypes = true>

let getDB() = DBSchema.GetDataContext(connectionString)

let db = getDB()

let objectId : Guid option = Guid.NewGuid() |> Some

query { for a in db.MySchema.MyTable do where (a.ObjectId = objectId) select a } |> List.ofSeq

### Expected behavior

Guid options to be treated as NULL when querying against the db when using 'UseOptionTypes'.

### Actual behavior

**Exception raised:**
`No mapping exists from object type Microsoft.FSharp.Core.FSharpOption`1[[System.Guid, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]] to a known managed provider native type.`

[Thorium]

I thought this would have been already working. As a workaround you can use:

query {
    for a in db.MySchema.MyTable do
    where (a.ObjectId.IsSome && a.ObjectId.Value = myGuid)
    select a
} |> List.ofSeq

[joelvandiver]

Thanks for the workaround!

I'm not sure why this isn't working either. I've had this Guid option for several months now and haven't run into until recently.

[Thorium]

I guess it was some change in SQL server driver. This should be also now fixed in version 1.1.94 by fe60096c1700ca78f7e8ba5948eda9f7be2ea35c