VB.NET Linq to Entities Query with child objects
Basically I have the follwing:
Dim ctx As New AdminCoreEntities
Dim roles = (From r In ctx.Roles where r.Name.StartsWith("cust") Select r) 'list of System.Linq.IQueryable(Of AdminCoreModel.Role)
Dim items = From i In ctx.QuickLinks.Include("Roles")
Where (i.TenantID = "470556ba-3574-4b01-a619-b85e9721b966" AndAlso i.Roles.Contains(roles))
Select New With {
i.ID,
i.Name,
.Roles = (From r In i.Roles Select New With {.Id = r.ID, .Name = r.Name})
}
The error i get when i run this i开发者_如何学运维s:
Unable to cast object of type System.Data.Objects.ObjectQuery`1[AdminCoreModel.Role] to type AdminCoreModel.Role
Basically I have a many to many situation and I try to get all the Quicklinks objects queried by their roles and not quite sure why EF will cast to a single AdminCoreModel.Role when i.Roles is a collections of objects.
Any help greatly appreciated
Well, .Contains()
expects one Role
, and you're passing it a list. That's what the error says.
Try (apologies in advance if I mangle the VB.NET syntax; I don't usually write VB.NET):
Dim ctx As New AdminCoreEntities
Dim items = From i In ctx.QuickLinks ' You don't need Include because you're projecting.
Where (i.TenantID = "470556ba-3574-4b01-a619-b85e9721b966"
AndAlso i.Roles.Any(Function(role) role.Name.StartsWith("cust"))
Select New With {
i.ID,
i.Name,
.Roles = (From r In i.Roles Select New With {.Id = r.ID, .Name = r.Name})
}
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