Develop Reference

Multiple AND conditions on the same column [Servicestack.OrmLite]

I was wondering if it's possible to have multiple AND conditions on the same column using Servicestack.OrmLite. This is the SELECT statement I printed out, but It always returns 0. I should get the product count from the products having both specifications with id 1016 and 17.
SELECT COUNT(DISTINCT "Product"."Id")
FROM "Product"
INNER JOIN "ProductManufacturer"
ON ("Product"."Id" = "ProductManufacturer"."ProductId")
INNER JOIN "ProductSpecificationAttribute"
ON ("Product"."Id" = "ProductSpecificationAttribute"."ProductId")
WHERE ("ProductManufacturer"."ManufacturerId" = 6)
AND ("ProductSpecificationAttribute"."SpecificationAttributeOptionId" = 1016)
AND ("ProductSpecificationAttribute"."SpecificationAttributeOptionId" = 17)

A single column value can't possibly have two values at the same time.
What you want is either:
AND
(
ProductSpecificationAttribute.SpecificationAttributeOptionId = 1016
OR
ProductSpecificationAttribute.SpecificationAttributeOptionId = 17
)
Or, more succinctly:
AND
(
ProductSpecificationAttribute.SpecificationAttributeOptionId
IN (1016, 17)
)
And turn off whatever option is forcing your tool to "inject" "double" "quotes" "around" "every" "entity" "name" because it makes the query text unmanageable. You might also consider using aliases and schema prefixes, like INNER JOIN dbo.ProductSpecificationAttribute AS psa...
After further clarification... the goal is to find products where they have both of those attributes on different rows, which isn't clear from the description or the code ORMLite barfed out. Here's what you want in that case (there are several ways to do this, but converting everything to EXISTS also allows you to remove the DISTINCT from the COUNT, which is never free):
SELECT COUNT(Product.Id) FROM dbo.Product AS p
WHERE EXISTS
(
SELECT 1 FROM dbo.ProductManufacturer AS pm
WHERE pm.ProductId = p.Id AND pm.ManufacturerId = 6
)
AND EXISTS
(
SELECT 1 FROM dbo.ProductSpecificationAttribute AS psa
WHERE psa.ProductId = p.Id
AND psa.SpecificationAttributeOptionId = 1016
)
AND EXISTS
(
SELECT 1 FROM dbo.ProductSpecificationAttribute AS psa
WHERE psa.ProductId = p.Id
AND psa.SpecificationAttributeOptionId = 17
);
If ProductSpecificationAttribute is poorly index and this leads to two scans, you could change that by saying something like this (untested, but I'm happy to test it out if you can produce a db<>fiddle:
SELECT COUNT(Product.Id) FROM dbo.Product AS p
WHERE EXISTS
(
SELECT 1 FROM dbo.ProductManufacturer AS pm
WHERE pm.ProductId = p.Id
AND pm.ManufacturerId = 6
)
AND EXISTS
(
SELECT 1 FROM dbo.ProductSpecificationAttribute AS psa
WHERE psa.ProductId = p.Id
AND psa.SpecificationAttributeOptionId IN (17, 1016)
GROUP BY psa.ProductId, psa.SpecificationAttributeOptionId
HAVING COUNT(DISTINCT psa.SpecificationAttributeOptionId) > 1
);
It's also really weird that the table ProductManufacturer has a list of ProductIDs in it that point back to Product - usually Product would have a ManufacturerID that points in the other direction.
Anyway, you might consider using stored procedures that your ORM can call if it has problems creating queries beyond basic CRUD (which is unfortunately a limitation of all ORMs to some degree - they're great at the basics, covering 80% of the use case, but they're terrible at the other 20% - unfortunately most of us end up needing that other 20% before too long).

You can get all the product ids that you want if you group by product and set the conditions in the HAVING clause:
SELECT p.Id
FROM Product p
INNER JOIN ProductManufacturer pm ON p.Id = pm.ProductId
INNER JOIN ProductSpecificationAttribute psa ON p.Id = psa.ProductId
WHERE pm.ManufacturerId = 6 AND psa.SpecificationAttributeOptionId IN (17, 1016)
GROUP BY p.Id
HAVING COUNT(DISTINCT psa.SpecificationAttributeOptionId) = 2; -- both specifications must exist
If you want to count these products you could either use the above query as a subquery or a cte and count the rows:
WITH cte AS (
SELECT p.Id
FROM Product p
INNER JOIN ProductManufacturer pm ON p.Id = pm.ProductId
INNER JOIN ProductSpecificationAttribute psa ON p.Id = psa.ProductId
WHERE pm.ManufacturerId = 6 AND psa.SpecificationAttributeOptionId IN (17, 1016)
GROUP BY p.Id
HAVING COUNT(DISTINCT psa.SpecificationAttributeOptionId) = 2;
)
SELECT COUNT(*) FROM cte;
or, use COUNT() window function:
SELECT DISTINCT COUNT(*) OVER ()
FROM Product p
INNER JOIN ProductManufacturer pm ON p.Id = pm.ProductId
INNER JOIN ProductSpecificationAttribute psa ON p.Id = psa.ProductId
WHERE pm.ManufacturerId = 6 AND psa.SpecificationAttributeOptionId IN (17, 1016)
GROUP BY p.Id
HAVING COUNT(DISTINCT psa.SpecificationAttributeOptionId) = 2;

How can I turn SQL query that joins two columns and groups by count of one column and a column of each joined table into LINQ?

In my database, each URI has associated tags (Tag table) and each pageview (PageView table) is associated with someone viewing a particular page. I want to return a list of URIs that have the same tags as a given URI, by count of each URI that shares those tag(s). My SQL query looks like this:
select count(URI) as 'Count', p.URI, t.Name
from tracking.PageView as p
inner join Tracking.Tag as t on p.ID = t.PageViewID
where t.name in
(select t.Name
from tracking.PageView as p
inner join Tracking.Tag as t on p.ID = t.PageViewID
where p.URI = 'URI WE WANT TAGS OF'
)
and p.uri like '%/articles/%'
group by p.URI , t.name
order by Count desc
My apologies if the description is too vague for the query or if the query itself is rough. It was just the first one that worked. I've tried to separate the subquery into a variable and select values in that subquery, but it's been some time since I've used LINQ and I'm spinning wheels at this point.

The following is pretty much an exact translation of your current SQL query, which should get you started.
from p in tracking.PageView
join t in Tracking.Tag on p.ID equals t.PageViewID
where p.uri.Contains("/articles/")
&& (
from p2 in tracking.PageView
join t2 in Tracking.Tag on p2.ID equals t2.PageViewID
where p2.URI == "URI WE WANT TAGS OF"
select t2.name
).Contains(t.name)
group new { p, t } by new { p.URI, t.name } into g
orderby g.Count() descending
select new {
Count = g.Count(),
g.Key.URI,
g.Key.Name
}

LEFT LINQ TO SQL C# JOIN on many to many table

Hi im kinda new to linq to sql I know about the basics. The problem is I want to do a left join in a query. There are 3 tables in the query.
Claimants ( all rows should be returned from this table)
Claim
User
The query should return all Users who have Claimants. This is done through the many to many table Claim. But regardless of Users all Claimants should be returned. Thus the left join on Claimants.
I have the following query
var d = (from Claimants in DB.Claimants
join Claims in DB.Claims on Claimants.Claiment_ID equals Claims.Claiment_ID
join Users in DB.Users on Claims.User_ID equals Users.User_ID
where (Claimants.TrialDate.Value >= dtDayStart & Claimants.TrialDate <= dtDayEnd)
select new
{
ClaimantFirstName = Claimants.FirstName,
ClaimantLasname = Claimants.LastName,
ClaimantsID = Claimants.IDNumber,
Claimants.OurReference,
Claimants.TrialDate,
InterviewStart = Claims.DateTimeStart,
InterviewEnd = Claims.DateTimeEnd,
Claims.Priority,
UserFirstname = Users.FirstName,
UserLastName = Users.LastName,
UserID = Users.IDNumber
});
I have tried using an into statement as follows but with no luck
var d = (from Claimants in DB.Claimants
join Claims in DB.Claims on Claimants.Claiment_ID equals Claims.Claiment_ID
into TheClaimants
from Claims in TheClaimants.DefaultIfEmpty()
join Users in DB.Users on Claims.User_ID equals Users.User_ID
where (Claimants.TrialDate.Value >= dtDayStart & Claimants.TrialDate <= dtDayEnd)
select new
{
ClaimantFirstName = Claimants.FirstName,
ClaimantLasname = Claimants.LastName,
ClaimantsID = Claimants.IDNumber,
Claimants.OurReference,
Claimants.TrialDate,
InterviewStart = Claims.DateTimeStart,
InterviewEnd = Claims.DateTimeEnd,
Claims.Priority,
UserFirstname = Users.FirstName,
UserLastName = Users.LastName,
UserID = Users.IDNumber
});
I would appreciate it if someone could point me in the right direction as to how to use these joins left right correctly and explain how the work. Thank you very much in advance.

var d = (from Claimants in DB.Claimants
join Claims in DB.Claims on Claimants.Claiment_ID equals Claims.Claiment_ID)
.DefaultIfEmpty()
join Users in DB.Users on Claims.User_ID equals Users.User_ID
where (Claimants.TrialDate.Value >= dtDayStart & Claimants.TrialDate <= dtDayEnd)
.DefaultIfEmpty()
select new
{
ClaimantFirstName = Claimants.FirstName,
ClaimantLasname = Claimants.LastName,
ClaimantsID = Claimants.IDNumber,
Claimants.OurReference,
Claimants.TrialDate,
InterviewStart = Claims.DateTimeStart,
InterviewEnd = Claims.DateTimeEnd,
Claims.Priority,
UserFirstname = Users.FirstName,
UserLastName = Users.LastName,
UserID = Users.IDNumber
});
Left outter join

You must know a Luan. If you want all the Claiments to return start by selecting from Claiments and then left join onto the other tables.
Try the following :
LINQ to SQL Left Outer Join

In LINQ, the ".Join()" extension method is the equivalent of SQL inner join.
For outer joins you have to use the ".GroupJoin()" extension method.
Assuming you know the .Join well, the GroupJoin is simple to use. I have to admit that when I first needed to do an outer join in LINQ it was damn hard to find out. I cannot fanthom why did they call it like that.
Although in VB.Net, here's an article that presents various SQL constructs translated into LINQ syntax, even if in VB, still easy to convert to extension methods: http://blogs.msdn.com/b/vbteam/archive/2007/12/31/converting-sql-to-linq-part-6-joins-bill-horst.aspx?Redirected=true
EDIT: #DavidB posted in his comments a much better solution, but only if you can use some ORM navigational properties. If you don't have them, then GroupJoin is probably the most reasonable

LINQ to EF, Left Join and group by clause

I have this SQL:
select o.prod_id, SUM(o.[count]) as [count]
into #otgr
from otgr o
where o.[date]<= #date
group by o.prod_id
select f.prod_id, SUM(f.[count]) as [count]
into #factory
from factory f
where f.[date]<= #date
group by f.prod_id
select p.name, p.id, f.[count] - ISNULL(o.[count],0) as av_count
from products p
join #factory f on f.prod_id = p.id
left join #otgr o on o.prod_id = p.id
where f.[count] - ISNULL(o.[count],0) > 0
How can I translate this into Linq? I'm stuck with this code:
from otgrr in db.otgr
where otgrr.date <= date
group otgrr by otgrr.prod_id into otgrs
from fac in db.factory
where fac.date <= date
group fac by fac.prod_id into facs
from prod in db.products
join fac2 in facs on prod.id equals fac2.Key
join otg2 in otgrs.DefaultIfEmpty(new {id = 0, av_count = 0 }) on prod.id equals otg2.Key
where (fac2.SUM(a=>a.av_count) - otg2.SUM(a=>a.av_count)) > 0
select new products { id = prod.id, name = prod.name, av_count = (fac2.SUM(a=>a.av_count) - otg2.SUM(a=>a.av_count))
Thank to everyone, and sorry for my bad english

You can also check LINQPad.
Of course, you can split this into multiple LINQ queries (after all, the execution is deferred, so it will be executed all as one single query, without using temporary tables. It should be faster in 99% of the cases).
But in your case it can be written more simply, by using navigation properties you probably have already set up:
var result= from p in products
select new {Name=p.Name,
Id = p.Id,
Count = p.Factories.Where(f=> f.date <= date).Sum(f=>f.Count)
- p.otgrs.Where(o=> o.date <= date).Sum(o=>o.Count)
};

Get only one (last) record in one-to-many join with linq-to-entities

I have the following in linq-to-entities
clientprojects = (from p in this.SAPMappingEntities.SAP_Master_Projects
join c in this.SAPMappingEntities.SAP_Master_ProjectPartners on c.project_no equals p.project_no
where c.partner_name.Contains(clientstring)
orderby p.start descending
select new ClientProjects { client = c.partner_name, location = c.city +", "+c.region, project_no = c.project_no, start_dt = p.start, end_dt = p.finish }).Take(50).ToList();
I would like change this query so that for each SAP_Master_Project only get the SAP_Master_ProjectPartners record which has the latest update_dt. How can I do this?
EDIT
There's a project table with a project number and project details including project start and end dates. There's a project partners table with the project partner number, name, project number, update date and other details.
SAP_MASTER_PROJECT
project_no
start
finish
SAP_MASTER_PROJECTPARTNERS
partner_no
project_no
partner_name
city
region
update_dt
When the user enters "ABC" into a text box, the info I want to return is the project number, project start date, project end date plus project partner name, city, and state from the last project partner record for the last 50 projects (based on start date) where the project partner name contains or is like "ABC".
I'm sure there's more than one way to do this, but his SQL gives me the results that I need:
SELECT TOP 50 p.project_no, p.start, p.finish, c.partner_name, c.city, c.region
FROM
(select pp.project_no, pp.partner_name, pp.city, pp.region
from SAP_Master_ProjectPartners pp
where pp.partner_name LIKE #clientstring AND pp.update_dt = (select max(pp1.update_dt)
from SAP_Master_ProjectPartners pp1
where pp1.project_no = pp.project_no)) c
join SAP_Master_Projects p
on (p.project_no = c.project_no)
ORDER BY p.start DESC
EDIT #2
That sql actually returns a few items which have the same update_dt, so I modified the sql to below. Still struggling to convert to linq.
SELECT TOP 50 p.project_no, p.start, p.finish, c.partner_name, c.city, c.region, c.update_dt, c.row_id
FROM SAP_Master_Projects p
join
(select pp.project_no, pp.partner_name, pp.city, pp.region, pp.update_dt, pp.row_id
from SAP_Master_ProjectPartners pp
where pp.partner_name LIKE #clientstring AND pp.row_id = (select TOP 1 row_id
from SAP_Master_ProjectPartners pp1
where pp1.project_no = pp.project_no order by update_dt DESC)) c
on (p.project_no = c.project_no) where p.active_flag = 1
ORDER BY p.start DESC

This query would probably be simpler if you defined an entity relationship between SAP_Master_Projects and SAP_Master_ProjectPartners so the join could be implicit instead of explicit.
Edit Since you can't do that, something like this might work (using let and doing a logical join within a where clause):
var clientProjects =
(
from p in entities.SAP_Master_Projects
let c = entities.SAP_Master_ProjectPartners
.Where(cl => cl.partner_name.Contains(clientstring)
&& cl.project_no == p.project_no
)
.OrderBy(cl => cl.update_dt) // Todo: Might need to be descending?
.FirstOrDefault()
where c != null
orderby p.start descending
select new ClientProjects
{
client = c.partner_name,
location = c.city + ", " + c.region,
project_no = c.project_no,
start_dt = p.start,
end_dt = p.finish
}
)
.Take(50)
.ToList()
;

It sounds like you're trying to come up with the following query:
SELECT *
FROM MasterProjects p
INNER JOIN (SELECT project_no,
partner_name
FROM ProjectPartners o
WHERE o.update_dt = (SELECT MAX(update_dt)
FROM ProjectPartners i
WHERE i.project_no = o.project_no)) c
ON p.project_no = c.project_no
AND p.partner_name = c.partner_name
I'm not entirely sure how to translate this in to LINQ but here is my best attempt:
var clientprojects =
from p in MasterProjects
join c in ProjectPartners on p.project_no == c.project_no
where c.partner_name == (from o in ProjectPartners
where o.project_no == c.project_no
and o.update_dt == (from i in ProjectParters
where o.project_no = i.project_no
select i.update_dt).Max()
select o.partner_name).First();
The above LINQ may not even compile, but hopefully it'll send you in the right direction.

I don't speak your language, sorry. But, for instance, in MySql you might add sort by update_dt DESC LIMIT 1 can you do that or somethign similar?