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

  • 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
     

    Friday, April 27, 2012 3:48 PM

Answers

  • 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

    Monday, April 30, 2012 2:49 AM
    Moderator

All replies

  • 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
    >
    >
    >
     
     
     
    Friday, April 27, 2012 5:13 PM
  • 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

    Monday, April 30, 2012 2:49 AM
    Moderator
  • 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......
     
     
    Wednesday, May 2, 2012 1:56 PM