While converting some of my code from VB to C# I'm having a hard time with this query:
Dim r = From v In VTab
Group v By v.ID Into g = Group
Select
ID,
Value = g.Where(Function(x) [...]).Sum(Function(x) x.Value),
Ann = (g.Where(Function(X) [...]).Count > 0)
From f In FTab.Where(Function(x) Value >= x.Min And Value <= x.Max).DefaultIfEmpty
Select New Result With {
.ID = ID,
.Value = Value,
.Ann = Ann,
.Data = f.Data
}
This basically groups values from VTab, obtaining one row per ID with a sum and a boolean, then joins this partial result with FTab and gives the final result.
This is the closest result I could get:
var r = from v in VTab
group v by v.ID into g
select g.Where(x => [...]).Sum(x => x.Value) into Value
from f in FTab.Where(x => Value >= x.Min && Value <= x.Max)
select new Result
{
Value = Value
};
I don't know how to specify multiple fields in the first select.
This is what I tried:
select g.Where(x => [...]).Sum(x => x.Value) into Value
select g.Where(x => [...]).Count() > 0 into Ann // g doesn't exist in the current context
// Syntax error
select g.Where(x => [...]).Sum(x => x.Value) into Value, g.Where(x => [...]).Count() > 0 into Ann
// Syntax error
select g.Where(x => [...]).Sum(x => x.Value) into Value,
select g.Where(x => [...]).Count() > 0 into Ann
// ; expected at the end of the line and I can't continue with the query
select new { Value = g.Where(x => [...]).Sum(x => x.Value), Ann = g.Where(x => [...]).Count() > 0}
How about this:
var r = VTab
.GroupBy(x => x.ID)
.Select(x => new {
ID = x.Key,
Value = x.Where(y => true).Sum(y => 1),
Ann = x.Where(y => true).Count() > 0
})
.Select(x => new Result() {
ID = x.ID,
Value = x.Value,
Ann = x.Ann,
Data = FTab.Where(y => x.Value >= y.Min && x.Value <= y.Max).FirstOrDefault()?.Data
});
After some more trial and error, I've been able to translate my query:
var r = from v in VTab
group v by v.ID into g
select new
{
ID = g.Key,
Value = g.Where(x => [...]).Sum(x => x.Value),
Ann = g.Where(x => [...]).Count() > 0}
} into t
from f in FTab.Where(x => t.Value >= x.Min && t.Value <= x.Max).DefaultIfEmpty()
select new Result
{
ID = t.ID,
Value = t.Value,
Ann = t.Ann,
Data = f?.Data
};
The key here is to use "into t" to identify the object created in the first select, and then refer to it in the second one.
Related
I am developing something to show a pie chart of the users' age with slicing them as
0-17
18-34
35-44
44-54
55+
Not Available
here i am getting the ages based on the date range;
var aggaResonse = client.Search<JSModel>(a => a
.Size(0)
.Query(q => q.Bool(b => b.Must(m => m
.DateRange(date => date
.Field(p => p.CreatedDate)
.GreaterThanOrEquals(start)
.LessThanOrEquals(end)),
m =>
m.Term(t => t.Field(f => f.StepType.Suffix("keyword")).Value("User"))
)
))
.Aggregations(c => c.DateRange(nameof(AgeModel), x => x
.Field(f => f.BirthDate)
.Ranges(r => r.From(DateMath.Now.Subtract("17y")).To(DateMath.Now).Key(nameof(result.Years_0_17)),
r => r.From(DateMath.Now.Subtract("34y")).To(DateMath.Now.Subtract("18y")).Key(nameof(result.Years_18_34)),
r => r.From(DateMath.Now.Subtract("44y")).To(DateMath.Now.Subtract("35y")).Key(nameof(result.Years_35_44)),
r => r.From(DateMath.Now.Subtract("54y")).To(DateMath.Now.Subtract("45y")).Key(nameof(result.Years_45_54)),
r => r.From(DateMath.Now.Subtract("120y")).To(DateMath.Now.Subtract("55y")).Key(nameof(result.Years_55_Plus))
)
)
));
if (!aggaResonse.IsValid)
return result;
result.Years_0_17 = aggaResonse.Aggregations.Range(nameof(AgeModel)).Buckets.Single(c => c.Key == nameof(result.Years_0_17)).DocCount;
result.Years_18_34 = aggaResonse.Aggregations.Range(nameof(AgeModel)).Buckets.Single(c => c.Key == nameof(result.Years_18_34)).DocCount;
result.Years_35_44 = aggaResonse.Aggregations.Range(nameof(AgeModel)).Buckets.Single(c => c.Key == nameof(result.Years_35_44)).DocCount;
result.Years_45_54 = aggaResonse.Aggregations.Range(nameof(AgeModel)).Buckets.Single(c => c.Key == nameof(result.Years_45_54)).DocCount;
result.Years_55_Plus = aggaResonse.Aggregations.Range(nameof(AgeModel)).Buckets.Single(c => c.Key == nameof(result.Years_55_Plus)).DocCount;
return result;
what i need is to have a "Not Available" slice for users who has NULL as birthdate with mapping it as;
result.Not_Available = ....;
Any suggestions with following best practices for nested NEST aggs ?
I was thinking to run another search which i guess it's not the best practice.
After digging documentations too much, here is the solution i wrote;
I added a "Missing" attribute to the current aggregation;
&& c.Missing("DOBMissing", x => x.Field(f => f.BirthDate))
So it became like;
.Aggregations(c => c.DateRange(nameof(AgeModel), x => x
.Field(f => f.BirthDate)
.Ranges(r => r.From(DateMath.Now.Subtract("17y")).To(DateMath.Now).Key(nameof(result.Years_0_17)),
r => r.From(DateMath.Now.Subtract("34y")).To(DateMath.Now.Subtract("18y")).Key(nameof(result.Years_18_34)),
r => r.From(DateMath.Now.Subtract("44y")).To(DateMath.Now.Subtract("35y")).Key(nameof(result.Years_35_44)),
r => r.From(DateMath.Now.Subtract("54y")).To(DateMath.Now.Subtract("45y")).Key(nameof(result.Years_45_54)),
r => r.From(DateMath.Now.Subtract("120y")).To(DateMath.Now.Subtract("55y")).Key(nameof(result.Years_55_Plus))
)
) &&
c.Missing("DOBMissing", x => x.Field(f => f.BirthDate))
)
And i'd accessed the "missing" part of aggregation as following;
result.Not_Available = aggaResponse.Aggregations.Missing("DOBMissing").DocCount;
I have the following LINQ
Dim z = (From d In db.GPSdevice
Where d.CompanyId = currentuser.CompanyId And d.Type = "Truck" Or d.Type = "Trailer"
Order By d.ListOrder Descending
Group d By d.Driver Into g = Group
Select g.FirstOrDefault())
I try to convert it to c#
var z = db.GPSdevices
.Where(p => p.CompanyId == companyID && p.Type == "Truck" || p.Type == "Trailer")
.OrderByDescending(p => p.ListOrder)
.GroupBy(p => p.Driver)
.Select(g => new { Group = g });
but not sure, how to convert Select g.FirstOrDefault()...
You can use the query syntax in C# too, no need to rewrite using the extension methods directly:
var z = (from d In db.GPSdevice
where (d.CompanyId == currentuser.CompanyId) && (d.Type == "Truck") || (d.Type == "Trailer")
orderby d.ListOrder descending
group d by d.Driver into g = group
select g.FirstOrDefault())
Just call g.FirstOrDefault() in your Select
var z = db.GPSdevices
.Where(p => p.CompanyId == companyID && p.Type == "Truck" || p.Type == "Trailer")
.OrderByDescending(p => p.ListOrder)
.GroupBy(p => p.Driver)
.Select(g => g.FirstOrDefault());
I've been puzzling over this problem all morning and can't figure out how to do it in C#.
My SQL query as follows:
select a.CourseID,
a.UserID
from audit a
inner join results r on a.UserID = r.UserID
inner join Course c on a.CourseID = c.CourseID
where c.CourseType = 9 and a.Guid = 'A123F123D123AS123123'
and a.Result = 'Passed' and r.Class = 'Maths'
group by a.CourseID, a.UserID
order by a.UserID
returns exactly what I want, but I can't seem to translate it into linq format. (the format being used here is what is required in my job at the moment so please advise on this format)
So far I have the following:
var audits = auditRepository.Get(a => a.Course.CourseType == 9 && a.GUID == this.Company.GUID && a.Result == "Passed", null, null,
a => a.Course, a => a.User)
.Join(resultsRepository.Get(r => r.GUID == this.Company.GUID && r.Class == class),
a => a.UserID,
r => r.UserID,
(a, r) => new Audit
{
User = a.User,
Course = a.Course,
Result = a.Result,
Timestamp = a.Timestamp,
AuditID = a.AuditID,
UserID = a.UserID
}
)
.OrderByDescending(o => o.Timestamp)
.GroupBy(u => new { u.User, u.Course })
.Select(grp => grp.ToList())
.ToList();
However this returns duplicates.
Any advice is appreciated, thanks
H
Instead of
.Select(grp => grp.ToList())
Select only the first element from each group to exclude duplicates:
.Select(grp => grp.First())
If you need a count also:
.Select(t => new{grp = t.First(),cnt = t.Count()} )
Fix:
.Select(t => new { grp = t.First(), cnt = t.Select(s => s.AuditID).Distinct().Count() })
I having two list or table as per below:
Query:
var q = db.tbl_User_to_CustomerMast
.Where(i => i.fk_Membership_ID == m.MembershipID)
.Join(
db.tbl_CustomerMast,
u => u.fk_Customer_ID,
c => c.CustomerID,
(u, c) => new { UserCustomer = u, Customer = c })
.Where(i => i.UserCustomer.fk_Store_ID == shopid).ToList();
Output:
List A:
User_Customer_ID Name
===================================
1 XYZ
2 ABC
Query:
var rewards = q.Join(
db.tbl_RewardAwardMast,
i => i.UserCustomer.User_Customer_ID,
j => j.fk_Customer_UserID,
(i, j) => new { Customer = i, Reward = j })
.Where(i => i.Reward.RewardDate >= i.Customer.UserCustomer.Membership_Start)
.GroupBy(i => i.Reward.fk_Customer_UserID)
.Select(i => new { CustomerID = i.Key, RewardCount = i.Count()})
.ToList();
Output:
List B:
User_Customer_ID RewardCount
===================================
1 5
Here is final Output Table
User_Customer_ID Name RewardCount
===============================================
1 XYZ 5
2 ABC 0
If I want to check that which user_customer_ID has less than 5 Reward Count, How I will Check:
Query:
var final = q.GroupJoin(
rewards,
i => i.UserCustomer.User_Customer_ID,
j => j.CustomerID,
(i, j) => new { Customer = i, Reward = j.DefaultIfEmpty() })
.Select(i => new { Count = i.Reward, id = i.Customer.UserCustomer.User_Customer_ID })
.ToList();
var final1 = final.Where(i => i.Count < m.MembershipMinVisit.Value).ToList();
Error:
Operator '<' cannot be applied to operands of type 'System.Collections.Generic.IEnumerable' and 'int'
You don't need a group join here as for each customer you need a single result (reward). Also because you need only customers with rewards < 5, an inner join using that condition wil give you what you want:
var final = q.Join( // Join instead of GroupJoin
rewards.Where(r => r.RewardCount < 5), // filter out rewards >= 5
i => i.UserCustomer.User_Customer_ID,
j => j.CustomerID,
(i, j) => new { Customer = i, Reward = j })
.Select(i => new {
Reward = i.Reward, // 'Count' is a bad name
// it is still the reward object
id = i.Customer.UserCustomer.User_Customer_ID
})
.ToList();
In your original query, Count (bad name) is a collection (IEnumerable) of awards, that's why you get that error. To fix it, you have to check that the single returned reward is not null (to filter out users without rewards at all, because you use a left join) and that it has a RewardCount less that 5:
var final1 = final.Where(i => i.Count.Single() != null &&
i.Count.Single().RewardCount < 5)
.ToList();
Trying to convert the below SQL query to LINQ, but I'm stuck at grouping by ClientCompany.
SELECT TOP 300 ClientCompany,
CASE WHEN MIN(FeatureID) = 12 THEN 1 ELSE 0 END as Sort
FROM Ad
LEFT JOIN AdFeature
ON Ad.ID = AdFeature.AdID
WHERE (AdFeature.FeatureID = 13 OR AdFeature.FeatureID = 12)
AND SiteID = 2
GROUP BY ClientCompany
ORDER BY Sort DESC
My attempt to convert this to LINQ:
(from a in Ads
join af in AdFeatures
on new {
join1 = a.ID,
join3 = 2
} equals new {
join1 = af.AdID,
join3 = af.SiteID
}
let sort = (
af.FeatureID == 12 ? 1 : 0
)
orderby sort descending
where af.FeatureID == 13 || af.FeatureID == 12
select new { a.ClientCompany, sort } ).Take(300)
How would I use MIN(FeatureID) and GROUP BY ClientCompany in LINQ, so that I only get a single row per ClientCompany back?
EDIT
This worked! Based on Daniel Hilgarth's answer. Is there anything that can go horribly wrong with this solution?
Ads.Join(AdFeatures, x => x.ID, x => x.AdID,
(a, af) => new { Ad = a, AdFeature = af })
.Where(x => x.AdFeature.FeatureID == 12 || x.AdFeature.FeatureID == 13)
.Where(x => x.AdFeature.SiteID == 2)
.GroupBy(x => x.Ad.ClientCompany)
.Select(g => new { ClientCompany = g.Key, Sort = g.Min(x => x.AdFeature.FeatureID) == 12 ? 1 : 0 })
.OrderByDescending(x => x.Sort)
.Take(300)
Try this:
Ads.Join(AdFeatures, x => x.FeatureID, x => x.FeatureID,
(a, af) => new { Ad = a, AdFeature = af })
.Where(x => x.AdFeature.FeatureID == 12 || x.AdFeature.FeatureID == 13)
.Where(x => x.AdFeature.SiteID == 2)
.GroupBy(x => x.Ad.ClientCompany)
.Select(g => new { ClientCompany = g.Key,
Sort = g.Min(x => x.AdFeature.FeatureID) == 12 ? 1 : 0 });
Please note, I changed the left outer join into an inner join, because your original query accesses AdFeature unconditionally, making it effectively an inner join .
hi I would write it like that
context.Ads.Where(ad => ad.AdFeatures.Any(feature => (feature.FeatureID == 13 || feature.FeatureID == 12) && feature.SiteID == 2))
.GroupBy(ad => ad.ClientCompany)
.Select(ads => new
{
cc = ads.Key, sort = ads.SelectMany(ad => ad.AdFeatures)
.Select(feature => feature.FeatureID)
.Min() == 12
})
.OrderBy(arg => arg.sort).Take(300);
Try this:
(from a in ads
join af in AdFeatures on a.ID equals af.AdID into g
from x in g.DefaultIfEmpty()
where x.FeatureID == 13 || x.FeatureID == 12
where x.SiteID == 2
orderby a.Sort descending
group a by a.ClientCompany into g2
from x2 in g2
let sort = g2.Select(T => T.FeatureID).Min() == 12 ? 1 : 0
select new { a.ClientCompany, Sort = sort }).Take(300);
Why do you need grouping anyway?