If you want to reduce the amount of memory, you can avoid generating a temporary list by using a generator: sum(x > 0 for x in frequencies) This works because bool is a subclass of int: >>> isinstance(True,int) True and True‘s value is 1: >>> True==1 True However, as Joe Golton points out in the … Read more
Try with a CASE in this way : SUM(CASE WHEN PaymentType = “credit card” THEN TotalAmount ELSE 0 END) AS CreditCardTotal, Should give what you are looking for …
My quick google with the terms “count unique values sqlite3” landed me on this post. However, I was trying to count the overall number of unique values, instead of how many duplicates there are for each category. From Chris’s result table above, I just want to know how many unique colors there are. The correct … Read more
You can do LINQ to Objects and the use LINQ to calculate the totals: decimal sumLineTotal = (from od in orderdetailscollection select od.LineTotal).Sum(); You can also use lambda-expressions to do this, which is a bit “cleaner”. decimal sumLineTotal = orderdetailscollection.Sum(od => od.LineTotal); You can then hook this up to your Order-class like this if you … Read more
You want to use the nullable form of Sum, so try casting your value to a nullable: from i in Db.Items select new VotedItem { ItemId = i.ItemId, Points = (from v in Db.Votes where b.ItemId == v.ItemId select v.Points).Sum(r => (decimal?) r.Points) } Your issue is discussed here in more detail: http://weblogs.asp.net/zeeshanhirani/archive/2008/07/15/applying-aggregates-to-empty-collections-causes-exception-in-linq-to-sql.aspx
This will do the trick: LINQ Query Syntax: from p in m.Items group p by 1 into g select new { SumTotal = g.Sum(x => x.Total), SumDone = g.Sum(x => x.Done) }; LINQ Method Syntax: m.Items .GroupBy(r => 1) .Select(g => new { SumTotal = g.Sum(x => x.Total), SumDone = g.Sum(x => x.Done) }); Notice … Read more
You can accomplish this by using Take & Sum: var list = new List<int>() { 1, 2, 3, 4 }; // 1 + 2 + 3 int sum = list.Take(3).Sum(); // Result: 6 If you want to sum a range beginning elsewhere, you can use Skip: var list = new List<int>() { 1, 2, 3, … Read more
var ListByOwner = list.GroupBy(l => l.Owner) .Select(lg => new { Owner = lg.Key, Boxes = lg.Count(), TotalWeight = lg.Sum(w => w.Weight), TotalVolume = lg.Sum(w => w.Volume) });
Wrap them up and use subqueries: SELECT (SELECT COUNT(*) FROM Toys WHERE little_kid_id = 900)+ (SELECT COUNT(*) from Games WHERE little_kid1 = 900 OR little_kid2 = 900 OR little_kid3 = 900) AS SumCount Voila!
You can sum numbers in a list simply with the sum() built-in: sum(your_list) It will sum as many number items as you have. Example: my_list = range(10, 17) my_list [10, 11, 12, 13, 14, 15, 16] sum(my_list) 91 For your specific case: For your data convert the numbers into int first and then sum the … Read more