How to write linq to sql to return records in leftt table where records do not exist in right table

Question

I need to return a list of records from my left table where they don't exist in the right table. I wrote T-sql that works but need to do it in linq,

Can someone assist?

thanks,

select distinct t.part_no,t.product_family  from  terminals t
Left join price_tier p on t.terminalid = p.terminalid
where
p.part_no is null
 

Answer 1

On 4/27/2012 11:48 AM, WTFHolmes wrote:

> I need to return a list of records from my left table where they don't

> exist in the right table. I wrote T-sql that works but need to do it in

> linq,

>

> Can someone assist?

>

> thanks,

>

> select distinct t.part_no,t.product_family  from  terminals t

> Left join price_tier p on t.terminalid = p.terminalid

> where

> p.part_no is null

>

>

>

 

http://msdn.microsoft.com/en-us/library/bb397895.aspx

 

http://www.linqpad.net/

 

Answer 2

Hi WTFHolmes,

Welcome to MSDN Forum.

If the terminals and price_tier are two datatables, please refer to the code below.

var list = (from t in terminals.AsEnumerable() join p in price_tier.AsEnumerable() 
on t["terminalid"] equals p["terminalid"] where p["part_no"] == null 
select new {t["part_no"],t["product_family"]}).ToList();

@darnold92 provided you some good links, if you want to learn LINQ, please refer to the links. Thanks for you sharing darnold92.

Best Regards

---

Allen Li [MSFT]
MSDN Community Support | Feedback to us

Answer 3

On 4/29/2012 10:49 PM, Allen_Li1988 wrote:

> Hi WTFHolmes,

>

> Welcome to MSDN Forum.

>

> If the terminals and price_tier are two datatables, please refer to the

> code below.

>

> var list = (from t in terminals.AsEnumerable() join p in price_tier.AsEnumerable()

> on t["terminalid"] equals p["terminalid"] where p["part_no"] == null

> select new {t["part_no"],t["product_family"]}).ToList();

>

> @darnold92 provided you some good links, if you want to learn LINQ,

> please refer to the links. Thanks for you sharing darnold92.

>

 

no problem......