Fix bug where MANY(...) on left join didn't work with nulls.

This was caused by the type generator incorrectly putting
BlueprintNoKeyAttribute on child types due to them having no sub column maps.

Author: rspeele

src/Rezoom.SQL.Mapping/DataReader.fs

@@ -36,7 +36,9 @@ let columnMap (reader : IDataReader) =
 type DataReaderRow(reader : IDataReader) =
     inherit Row()
     override __.IsNull(i) = reader.IsDBNull(int i)
-    override __.GetObject(i) = reader.GetValue(int i)
+    override __.GetObject(i) =
+        let o = reader.GetValue(int i)
+        if obj.ReferenceEquals(o, DBNull.Value) then null else o
     override __.GetString(i) = reader.GetString(int i)
     override __.GetByte(i) = reader.GetByte(int i)
     override __.GetInt16(i) = reader.GetInt16(int i)

src/Rezoom.SQL.Mapping/Row.fs

@@ -24,7 +24,7 @@ type Row() =
 
 type ObjectRow([<ParamArray>] row : obj array) =
     inherit Row()
-    override __.IsNull(i) = isNull (row.[int i])
+    override __.IsNull(i) = isNull (row.[int i]) || obj.ReferenceEquals(DBNull.Value, row.[int i])
     override __.GetObject(i) = row.[int i]
     override __.GetString(i) = row.[int i] |> Unchecked.unbox
     override __.GetByte(i) = row.[int i] |> Unchecked.unbox

src/Rezoom.SQL.Provider/TypeGeneration.fs

@@ -102,7 +102,7 @@ let private addScalarInterface (ty : ProvidedTypeDefinition) (field : ProvidedFi
     ty.DefineMethodOverride(getterMethod, getScalarValue)
     ty.AddMember(getterMethod)
 
-let rec private generateRowTypeFromColumns (model : UserModel) name (columnMap : CompileTimeColumnMap) =
+let rec private generateRowTypeFromColumns isRoot (model : UserModel) name (columnMap : CompileTimeColumnMap) =
     let ty =
         ProvidedTypeDefinition
             ( name
@@ -111,7 +111,7 @@ let rec private generateRowTypeFromColumns (model : UserModel) name (columnMap :
             , HideObjectMethods = true
             )
     ty.AddCustomAttribute(SerializableAttributeData())
-    if not columnMap.HasSubMaps then
+    if isRoot && not columnMap.HasSubMaps then
         ty.AddCustomAttribute(BlueprintNoKeyAttributeData())
     let fields = ResizeArray()
     let addField pk (name : string) (fieldTy : Type) =
@@ -139,7 +139,7 @@ let rec private generateRowTypeFromColumns (model : UserModel) name (columnMap :
         let info = column.Expr.Info
         addField info.PrimaryKey name <| info.Type.CLRType(useOptional = (model.Config.Optionals = Config.FsStyle))
     for KeyValue(name, subMap) in columnMap.SubMaps do
-        let subTy = generateRowTypeFromColumns model (toRowTypeName name) subMap
+        let subTy = generateRowTypeFromColumns false model (toRowTypeName name) subMap
         ty.AddMember(subTy)
         addField false name subTy
     let ctorParams = [ for camel, field in fields -> ProvidedParameter(camel, field.FieldType) ]
@@ -159,7 +159,7 @@ let rec private generateRowTypeFromColumns (model : UserModel) name (columnMap :
 
 let private generateRowType (model : UserModel) (name : string) (query : ColumnType QueryExprInfo) =
     CompileTimeColumnMap.Parse(query.Columns)
-    |> generateRowTypeFromColumns model name
+    |> generateRowTypeFromColumns true model name
 
 let private maskOfTables (model : UserModel) (tables : QualifiedObjectName seq) =
     let mutable mask = BitMask.Zero

src/Rezoom.SQL.Test/TestCompositeReaders.fs

@@ -4,6 +4,7 @@ open FsUnit
 open Rezoom.SQL.Mapping
 open Rezoom.SQL.Mapping.CodeGeneration
 open System
+open System.Globalization
 open System.ComponentModel.DataAnnotations
 
 type User = 
@@ -18,6 +19,20 @@ type Folder =
         Children : Folder array
     }
 
+type ManyWithStuffChild =
+    {
+        [<BlueprintKey>]
+        ChildId : int
+        ChildTime : DateTime
+    }
+type ManyWithStuff =
+    {
+        [<BlueprintKey>]
+        ThingId : int
+        ThingTime : DateTime
+        Children : ManyWithStuffChild array
+    }
+
 type Person =
     {
         PersonId : int
@@ -145,6 +160,26 @@ let ``read folder 2 levels deep`` () =
     Assert.AreEqual(0, folder.Children.[0].Children.Length)
     Assert.AreEqual(0, folder.Children.[1].Children.Length)
 
+[<Test>]
+let ``read manywithstuff children null`` () =
+    let colMap =
+        [|
+            "ThingId", ColumnType.Int32
+            "ThingTime", ColumnType.String
+            "Children.ChildId", ColumnType.Int32
+            "Children.ChildTime", ColumnType.String
+        |] |> ColumnMap.Parse
+    let reader = ReaderTemplate<ManyWithStuff array>.Template().CreateReader()
+    reader.ProcessColumns(colMap)
+    reader.Read(ObjectRow(1, DateTime.MinValue.ToString(CultureInfo.InvariantCulture), DBNull.Value, DBNull.Value))
+    reader.Read(ObjectRow(2, DateTime.MaxValue.ToString(CultureInfo.InvariantCulture), DBNull.Value, DBNull.Value))
+    reader.Read(ObjectRow(3, DateTime.MaxValue.ToString(CultureInfo.InvariantCulture), DBNull.Value, DBNull.Value))
+    let things = reader.ToEntity()
+    Assert.IsNotNull(things)
+    Assert.AreEqual(3, things.Length)
+    for thing in things do
+        Assert.AreEqual(0, thing.Children.Length)
+
 [<Test>]
 let ``read person 1 level deep`` () =
     let colMap =

src/TypeProviderUsers/TypeProviderUser.SQLite/TestSelects.fs

@@ -94,6 +94,20 @@ let ``test optional guid parameter`` () =
     let results = TestOptionalGuidParameter.Command(Some (Guid.NewGuid())) |> runOnTestData
     printfn "%A" results
 
+type TestEmptyMany = SQL<"""
+select p.*, many Children(c.*)
+from Users p
+left join Users c on false
+""">
+
+[<Test>]
+let ``test empty many`` () =
+    let results = TestEmptyMany.Command() |> runOnTestData
+    Assert.AreEqual(2, results.Count)
+    for result in results do
+        Assert.AreEqual(0, result.Children.Count)
+    printfn "%A" results
+
 [<Test>]
 let ``replay works`` () =
     let plan =