How do I write this linq command to an equivalent delete SQL query?

Question

I haven't written SQL in many years and now I'm working on a little more "performance hungry" site. Could someone please help me convert this to a delete SQL command?

I have a bunch of these so helping me with this one would sort out a lot for me, thanks!

I got this far:

Delete FROM [DbName].[dbo].[RatingListTriangleModels] 
WHERE  ...

Linq select command:

var allRatingListObjects = from row in ctx.RatingListTriangle
                           where
                              (row.To1Id == myToid && row.To2Id == theirTradeObjectid)
                               || (row.To2Id == myToid && row.To3Id == theirTradeObjectid)
                               || (row.To3Id == myToid && row.To1Id == theirTradeObjectid)
                           select row;

Update: Here is the working solution I went for:

using (SqlCommand command = new SqlCommand
                ("delete TBL from RatingListTriangleModels TBL where ( TBL.To1Id = @MY_ID and TBL.To2Id = @OTHER_ID ) or ( TBL.To2Id = @My_ID and TBL.To3Id = @OTHER_ID ) or ( TBL.To3Id = @My_ID and TBL.To1Id = @OTHER_ID )", cn))
            {
                // Add new SqlParameter to the command.
                command.Parameters.Add(new SqlParameter("MY_ID", myToid));
                command.Parameters.Add(new SqlParameter("OTHER_ID", theirTradeObjectid));
                var no = command.ExecuteNonQuery();
            }

Answer 1

This should delete the records you specify in your linq-statement but you need to replace @YOUR_ID and @OTHER_ID with the corresponding ids you have.

You can do this with SqlParameter . Example

delete from [DbName].[dbo].[RatingListTriangleModels] TBL
where ( TBL.To1Id = @YOUR_ID and TBL.To2Id = @OTHER_ID )
   or ( TBL.To2Id = @YOUR_ID and TBL.To3Id = @OTHER_ID )
   or ( TBL.To3Id = @YOUR_ID and TBL.To1Id = @OTHER_ID )  

Answer 2

If you want to delete the rows that that linq selects with TSQL you could do

DECLARE @p0 int;
DECLARE @p1 int;
SET @p0 = <some integer>;
SET @p1 = <some other integer>;


DELETE
            [DbName].[dbo].[RatingListTriangleModels]
    WHERE
            ([To1Id] = @p0 AND [To2Id] = @p1)
        OR  
            ([To2Id] = @p0 AND [To3Id] = @p1)
        OR
            ([To3Id] = @p0 AND [To1Id] = @p1);

Of course you'll probably want to pass the statement to ExecuteCommand on your context and pass the ids as a parameters, then .Net will wrap this in a call to sp_executeSql for you. This will protect from injection attacks, give you the benefits of query plan reuse and the flexibility of direct TSQL manipulation.

I would caveat my answer, a simple operation like this would problably be performed equivalently in linq without any of this additional complication.