Question

I have a perplexing SQL select statement (ugly) that I’m trying to write in LINQ. I’m working to get a single statment that will execute, not pre-selected data into lists that I have to send back to the server.

DECLARE @StartDate DATETIME ;
DECLARE @EndDate DATETIME ;
SET @pStartDate = '20100501'
SET @pEndDate = '20100531'

SELECT r.company ,r.trandate ,r.currency ,r.account ,r.credit ,r.debit
FROM   dbo.Register r
INNER JOIN dbo.CompanyList c ON r.company = c.company
WHERE  
r.trandate BETWEEN @pStartDate AND @pEndDate
AND LEN(r.currency) > 0
AND ( 
    ( r.account = 'XXX-ZZZ' )
    OR
    ( LEFT(r.account, 3) IN ( SELECT LEFT(code, 3) FROM dbo.investments ))
    OR 
    ( r.account IN ( 
        SELECT account FROM dbo.CompanyInfo WHERE company = r.company
                   AND ( ( dateclosed IS NULL )
                   OR dateclosed >= @pStartDate) ) )
    )

This is an example that contains the problem code – a WHERE clause with a triple OR expression. I’ve tried using three different queries then concat() or union() which returns incorrect reccord count because a record may match multiple expressions. I’m going to try rearranging logic and create a new TSQL version that may help me find a solution in LINQ.

Ideas welcome.

Answer 1

Since LINQ-to-SQL supports TSQL via ExecuteQuery – why re-write something that works? Complex queries may well deserve a bit of hand-cranking. I would just leave “as is”, and simply substitute:

SET @pStartDate = {0}
SET @pEndDate = {1}

which will be injected when you call

var data = ctx.ExecuteQuery<RegisterQueryResult>(tsql, startDate, endDate);