datatable column allows null if there is default constraint as well (was originally handled in serialization of columns by coalescing both boolean in the serialized format)

Author: smoothdeveloper

src/SqlClient/Shared.fs

@@ -232,7 +232,7 @@ module RuntimeInternals =
         let primaryKey = ResizeArray()
         for column in columns do
             let col = new DataColumn(column.Name,column.TypeInfo.ClrType)
-            col.AllowDBNull <- column.Nullable
+            col.AllowDBNull <- column.Nullable || column.HasDefaultConstraint
             col.ReadOnly <- column.ReadOnly
             col.AutoIncrement <- column.Identity