convert dictionary to list model - c#

var entity = await _abcRepository.get(Id);
var X = entity.GroupBy(c => c.number).Where(grp => grp.Count() == 1).Take(10).ToList();
in images you see [0] and inside of it one more [0].
How can I get that model value.
X[0][0] is not working.
X.Value is not working.
I need to convert that dictionary to model.

Use .Select to normalize aggregation as per your wish.
var X = entity.GroupBy(c => c.number).Where(grp => grp.Count() == 1)
.Select(group => new { GroupKey = group.Key, Items = group.ToList() })
.Take(10).ToList();

You could try something like this:
var entity = await _abcRepository.get(Id);
var results = entity.GroupBy(c => c.number)
.Where(grp => grp.Count() == 1)
.Take(10)
.ToDictionary(grp => grp.Key, grp => grp.First());
Essentially, the lambda you pass in Where method certifies that the groups are created contains only one item. That being said, you can use the First on each group to fetch that one element.

Related

Convert Sql to linq with groupby

I have view on which I use this request
Select Spendband, SUM(SpendCurrencyJob), SUM(SpendDocumentCount)
From analysis.vwJobSupplierMetrics
Where JobId = '500E0DD1-E3D3-4887-95EF-01D3C9EA8FD0'
Group by SpendBand
And it's running sucessfully
and get me this data
How I need to write it using linq to get same data?
I tried like this
var data = await _dbContext.VwJobSupplierMetrics.Where(x => x.JobId == jobId)
.GroupBy(x => x.SpendBand)
.Select(x => new HumpChartDto() {SpendBand = x.SpendBand}).ToListAsync();
But on new HumpChartDto() {SpendBand = x.SpendBand} I got Cannot resolve symbol 'SpendBand
How I can solve this?
First, after grouping on SpendBand, you need to access it via Key property. Second, to compute Sum, you can use Sum method.
var data = await _dbContext.VwJobSupplierMetrics.Where(x => x.JobId == jobId)
.GroupBy(x => x.SpendBand)
.Select(x => new HumpChartDto()
{
SpendBand = x.Key,
SumOfSpendCurrencyJob = x.Sum(s => s.SpendCurrencyJob),
SumOfSpendDocumentCount= x.Sum(s => s.SpendDocumentCount),
})
.ToListAsync();
Note - change the property name accordingly for name I've used for SumOfSpendCurrencyJob and SumOfSpendDocumentCount as don't know the definition of HumpChartDto class.

How to order groupBy items

Having this Linq query which returns grouping of 4 DateTime:
IEnumerable<IGrouping<DateTime, QuoteSnapshotModel>> lista = (from q in quoteModeList
where q.QuoteTradeType == "Q"
select q).GroupBy(n => n.ExceriseDate);
How can I order the groups by DateTime and get only the first group?
meaning **List<QuoteSnapshotModel>**
Also, how can I get only the second List<QuoteSnapshotModel> (according to DateTime)
Try this:
for this you have to create a list<QuoteSnapshotModel> within class QuoteSnapshotModel.
int record = 1;
List<QuoteSnapshotModel> result =
quoteModeList
.Where(x => x.QuoteTradeType == "Q")
.GroupBy(x => x.ExceriseDate,
(a, b) => new QuoteSnapshotModel
{
ExceriseDate = a,
ListQuoteSnapshotModel = b.ToList()
})
.OrderByDescending(t => t.ExceriseDate)
.Skip(record - 1).Take(1).ToList();
Update
You can use only the first group
List<QuoteSnapshotModel> list =quoteModeList.Where(x=>x.QuoteTradeType =="Q")
.GroupBy(x => x.ExceriseDate)
.OrderBy(x=>x.Key)
.FirstOrDefault().Select(x=>x.QuoteTradeType).ToList();
You can use only the second group
List<QuoteSnapshotModel> list =quoteModeList.Where(x=>x.QuoteTradeType =="Q")
.GroupBy(x => x.ExceriseDate)
.OrderBy(x=>x.Key)
.Skip(1).First().Select(x=>x.QuoteTradeType).ToList()
How can I order the groups by DateTime
.OrderBy(g => g.Key) or .OrderBy(g => g.First().ExerciseDate)
and get only the first group?
.First() (or .FirstOrDefault() if it's possible there are 0 groups)
how can I get only the second List (according to DateTime)
.Skip(1).Take(1) or .ElementAt(1) or .Skip(1).First()
Putting it all together:
IEnumerable<IGrouping<DateTime, QuoteSnapshotModel>> lista = (
from q in quoteModeList
where q.QuoteTradeType == "Q"
select q
).GroupBy(n => n.ExerciseDate);
IList<QuoteSnapshotModel> firstQuote = lista.OrderBy(x => x.Key).Select(x => x.ToList()).FirstOrDefault();
IList<QuoteSnapshotModel> secondQuote = lista.OrderBy(x => x.Key).Skip(1).Select(x => x.ToList()).FirstOrDefault();

Join an array of string with the result of an existing linq statement

As a follow up to my last question here:
Filtering a list of HtmlElements based on a list of partial ids
I need to take this statement:
doc.All.Cast<HtmlElement>()
.Where(x => x.Id != null)
.Where(x => ids
.Any(id => x.Id.Contains(id))).ToList();
and join it with an array of strings called fields. Assuming the array and list will have the same amount of elements each and line up correctly. I tried using Zip() but thought I might need to use an additional linq statement to make it work.
Assuming that fieldList[0] and IdList[0] corresponding to each other, you can do the following:
var IdList = doc.All.Cast<HtmlElement>()
.Where(x => x.Id != null)
.Where(x => ids
.Any(id => x.Id.Contains(id))).ToList();
var resultList = fieldList
.Select( (item, index) => new { Field = item, Id = IdList[index] })
.ToDictionary(x => x.Id, x => x.Field);
You have mentioned it already, you can use Enumerable.Join:
var joined = from id in fields
join ele in elements on id equals ele.Id
select new { Element = ele, ID = id };
var dict = joined.ToDictionary(x => x.ID, x => x.Element);
I've presumed that you want to join them via ID. I've also presumed that the string[] contains only unique ID's. Otherwise you need to use Distinct.

Query entity and return back a dictionary

I'm trying to query a view (entity) from the database and return back a dictionary. There are duplicates in the view so I tried groupby and I can't figure it out.
var queryresults = db.MyView.Where(x => x.year == myYear)
.GroupBy(g => new { g.myCode, g.myCodeName})
.ToDictionary(d => d.myCode, d => d.myCodeName);
You should group by dictionary key property if you want to avoid duplicate keys error. Then you can select code name of first item in each group as dictionary entry value:
var queryresults =
db.MyView.Where(x => x.year == myYear)
.GroupBy(x => x.myCode)
.ToDictionary(g => g.Key, g => g.First().myCodeName);

Find MAX/MIN list item using LINQ?

I have a list Having multiple Items and 3 props ID,DATE,COMMENT.ID field is Auto incremented in DATABASE.
Let say list Contains
2,16AUG,CommentMODIFIED
1,15AUG,CommentFIRST
3,18AUG,CommentLASTModified
I want to get a single ITEM.Item Having Minimum DATE and having Latest Comment. In this case
1,15AUG,CommentLASTModified
Any easy way to do it using LINQ.
orderedItems = items.OrderBy(x => x.Date);
var result = items.First();
result.Comment = items.Last().Comment;
To get a single item out of the list, you can order the items then take the first one, like this:
var result = items
.OrderByDescending(x => x.Date)
.First();
But First will throw an exception if the items collection is empty. This is a bit safer:
var result = items
.OrderByDescending(x => x.Date)
.FirstOrDefault();
To get the min / max of different columns you can do this:
var result =
new Item {
Id = 1,
Date = items.Min(x => x.Date),
Comment = items.Max(x => x.Comment)
};
But this will require two trips to the database. This might be a bit more efficient:
var result =
(from x in items
group x by 1 into g
select new Item {
Id = 1,
Date = g.Min(g => g.Date),
Comment = g.Max(g => g.Comment)
})
.First();
Or in fluent syntax:
var result = items
.GroupBy(x => 1)
.Select(g => new Item {
Id = 1,
Date = g.Min(g => g.Date),
Comment = g.Max(g => g.Comment)
})
.First();

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