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I'm trying to select the top five most frequent values in my table and return them in a List.
var mostFollowedQuestions = (from q in context.UserIsFollowingQuestion select *top five occuring values from q.QuestionId*).toList(); Any idea?
Thanks
605
The Any operator is used to check whether any element in the sequence or collection satisfy the given condition. If one or more element satisfies the given condition, then it will return true. If any element does not satisfy the given condition, then it will return false.
LINQ syntax is typically less efficient than a foreach loop. It's good to be aware of any performance tradeoff that might occur when you use LINQ to improve the readability of your code. And if you'd like to measure the performance difference, you can use a tool like BenchmarkDotNet to do so.
The Select() method invokes the provided selector delegate on each element of the source IEnumerable<T> sequence, and returns a new result IEnumerable<U> sequence containing the output of each invocation.
Yes, LINQ uses lazy evaluation. The database would be queried when the foreach starts to execute, but it would fetch all the data in one go (it would be much less efficient to do millions of queries for just one result at a time).
var mostFollowedQuestions = context.UserIsFollowingQuestion .GroupBy(q => q.QuestionId) .OrderByDescending(gp => gp.Count()) .Take(5) .Select(g => g.Key).ToList(); 
int[] nums = new[] { 1, 1, 1, 2, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7 }; IEnumerable<int> top5 = nums .GroupBy(i => i) .OrderByDescending(g => g.Count()) .Take(5) .Select(g => g.Key); If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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