Question

I can’t work out how to convert this into Linq. Any help appreciated!

SELECT distinct top 5 searchterm, created
FROM
(   SELECT searchterm, created ,ROW_NUMBER() 
    over(partition by searchterm order by created) Ordresults, createdby
    FROM searchhistory 
) A
WHERE A.Ordresults = 1 and A.CreatedBy = 'USERNAME'
ORDER BY A.Created DESC

Answer 1

Something like this should work:

Query syntax:
Take is not supported, so it has to be called as an extension method:

var query = (from term in EM.SearchHistory
            group term by term.searchterm into g
            let item = new 
            { 
                searchterm = g.Key, 
                first = g.OrderBy(t => t.created).First(),
            }
            where item.first.createdby == "USERNAME"
            orderby item.first.created
            select new
            {
                item.searchterm,
                item.first.created,
            })
            .Take(5)
;

Method syntax:

var query = EM.SearchHistory
    .GroupBy(term => term.searchterm)
    .Select(g => new 
    {
        searchterm = g.Key, 
        first = g.OrderBy(t => t.created).First(),
    })
    .Where(item => item.first.createdby == "USERNAME")
    .OrderBy(item => item.first.created)
    .Select(item => new
    {
        item.searchterm,
        item.first.created,
    })
    .Take(5)
;