Type Inference and LINQ

[Masa Ito]

I am really jazzed about LINQ - but am struggling with some basics -
like when does it infer the datatype?

Simple example - I want to get all the tables in a typed dataset that
have "RAW" in the name. I would have thought that:

Dim qRawTables = From RawTable In ds.Tables _
Where RawTable.TableN ame.ToString.St artsWith("RAW")

When I hover over qRawTables it is an object. So it is not using type
inferrence right? ds.tables is returning a
System.Data.Dat aTableCollectio n - but this isn't ienumerable? I can
add .AsQueryable but then the RawTable.TableN ame gets a 'Late Binding'
error.

Sorry for a possibly stupid question!

[Cor Ligthert[MVP]]

Re: Type Inference and LINQ

Maso,

Have you option strict On?

Dim qRawTables = From RawTable In ds.Tables _
Where DirectCast(RawT able,
DataTable).Tabl eName.StartsWit h("RAW")

Cor

[Masa Ito]

Re: Type Inference and LINQ

On 2008-02-11 21:21:19 -0500, "Cor Ligthert[MVP]" said:

Have you option strict On?
>
Dim qRawTables = From RawTable In ds.Tables _
Where DirectCast(RawT able,
DataTable).Tabl eName.StartsWit h("RAW")

Cor,

Thanks (as always!)

I didn't think to try a DirectCast - it works great. I also tried
doing from RawTable as Datable and it worked... like this:

Dim qRawTables = From Rawtable as Datatable in ds.Tables _
Where Rawtable.TableN ame.StartsWith( "RAW")

Do you know why it doesn't already know that RawTable is a datatable?
Other queries that I do are able to infer the type - is it because
ds.Tables could return other things than datatables?

[Cor Ligthert[MVP]]

Re: Type Inference and LINQ

Masa,

How can it know that it is a datatable and not a relation.

Cor