If the person you are searching is a CIA emplyee, take his CIAJobs.EmployerID, otherwise select People.ID
SELECT
case when CIAJobs.EmployeeID IS NULL then People.ID
else CIAJobs.EmployerID
end
FROM [FMO].[People] AS p
LEFT JOIN [FMO].[CIAJobs] j
ON (p.ID = j.[EmployeeID])
AND (j.[relationshipType] = '25a8d79d-377e-4108-8c92-0ef9a2e1ab63')
where p.ID = '1b66e032-94b2-e811-96e0-f48c508e38a2' // id of person you search for
OR
j.[EmployeeID] = '1b66e032-94b2-e811-96e0-f48c508e38a2' // id of person you search for
I tried doing this in Linq:
var a = from l in People
join x in CIAJobs
on l.Id equals x.EmployeeID && x.RelationshipTypeGuid equals Guid.Parse('25a8d79d-377e-4108-8c92-0ef9a2e1ab63')
into gcomplex
from xx in gcomplex.DefaultIfEmpty()
select (xx.EmployeeID == null) ? l.EmployeeId : x.EmployerID;
var b = a.ToList();
why does the query show an error because of this chunk: && x.RelationshipTypeGuid equals Guid.Parse('25a8d79d-377e-4108-8c92-0ef9a2e1ab63')
If I remove this part it shows no error.
Error is: operator && cannot be applied to operands of type Guid and Guid.
Can you help me correct the Linq query please logically and syntactically? Thank you.
You don't need join for multiple conditions in this scenario. Use this
var a = from l in People
join x in CIAJobs
.Where(z=>z.RelationshipTypeGuid
.Equals(Guid.Parse('25a8d79d-377e-4108-8c92-0ef9a2e1ab63')))
on l.Id equals x.EmployeeID
into gcomplex
from xx in gcomplex.DefaultIfEmpty()
select (xx.EmployeeID == null) ? l.EmployeeId : x.EmployerID;
var b = a.ToList();
But based on your problem statement this should do
var a = from l in People
join x in CIAJobs
on l.Id equals x.EmployeeID
into gcomplex
from xx in gcomplex.DefaultIfEmpty()
select (xx == null) ? l.EmployeeId : xx.EmployerID;
var b = a.ToList();
SELECT ra.ResidentID, ra.RoomID, r.Number, ra.StartDate, p.FacilityID
FROM(
SELECT ResidentID, MAX(StartDate) AS max_start
FROM RoomAssignments
GROUP BY ResidentID
) m
INNER JOIN RoomAssignments ra
ON ra.ResidentID = m.ResidentID
AND ra.StartDate = m.max_start
INNER JOIN Rooms r
ON r.ID = ra.RoomID
INNER JOIN Person p
ON p.ID = ra.ResidentID
inner join ComplianceStage cs
ON cs.Id = p.ComplianceStageID
ORDER BY ra.EndDate DESC
I'm trying to figure out how to convert this to C# using LINQ. I'm brand new with C# and LINQ and can't get my subquery to fire correctly. Any chance one of you wizards can turn the lights on for me?
Update-----------------
I think I've got the jist of it, but am having trouble querying for the max startdate:
var maxQuery =
from mra in RoomAssignments
group mra by mra.ResidentID
select new { mra.ResidentID, mra.StartDate.Max() };
from ra in RoomAssignments
join r in Rooms on ra.RoomID equals r.ID
join p in Persons on ra.ResidentID equals p.ID
where ra.ResidentID == maxQuery.ResidentID
where ra.StartDate == maxQuery.StartDate
orderby ra.ResidentID, ra.StartDate descending
select new {ra.ResidentID, ra.RoomID, r.Number, ra.StartDate, p.FacilityID}
Following my LINQ to SQL Recipe, the conversion is pretty straight forward if you just follow the SQL. The only tricky part is joining the range variable from the subquery for max start date to a new anonymous object from RoomAssignments that matches the field names.
var maxQuery = from mra in RoomAssignments
group mra by mra.ResidentID into mrag
select new { ResidentID = mrag.Key, MaxStart = mrag.Max(mra => mra.StartDate) };
var ans = from m in maxQuery
join ra in RoomAssignments on m equals new { ra.ResidentID, MaxStart = ra.StartDate }
join r in Rooms on ra.RoomID equals r.ID
join p in Persons on ra.ResidentID equals p.ID
join cs in ComplianceStage on p.ComplianceStageID equals cs.Id
orderby ra.EndDate descending
select new {
ra.ResidentID,
ra.RoomID,
r.Number,
ra.StartDate,
p.FacilityID
};
Here is my LINQ query with multiple joins:
it is working good but I need to do an enhancement in its working.
var selectedResults=
from InvoiceSet in Invoices
join BookedAreaSet in BookedAreas on InvoiceSet.InvoiceID equals BookedAreaSet.InvoiceID
join AreaSet in Areas on BookedAreaSet.AreaID equals AreaSet.AreaID
join ContactSet in Contacts on InvoiceSet.ContactID equals ContactSet.ContactID
join Contacts_ObjectsSet in Contacts_Objects on ContactSet.ContactID equals Contacts_ObjectsSet.ContactID
join CompanySet in Companies on Contacts_ObjectsSet.ObjectReferenceID equals CompanySet.CompanyID
join Customer_CustomerGroupSet in Customer_CustomerGroup on Contacts_ObjectsSet.ObjectReferenceID equals Customer_CustomerGroupSet.CustomerID
join CustomerGroupDiscountsSet in CustomerGroupDiscounts on Customer_CustomerGroupSet.CustomerGroupID equals CustomerGroupDiscountsSet.ID
join InvoiceStatusSet in InvoiceStatus on InvoiceSet.InvoiceStatusID equals InvoiceStatusSet.ID
where Contacts_ObjectsSet.ObjectReference=="Company"
//let minDate=(BookedAreaSet.LeasedDate).Min() where BookedAreaSet.InvoiceID=InvoiceSet.InvoiceID
select new {licensee=(CompanySet.CompanyName),CustomerGroupDiscountsSet.CustomerGroup,AreaSet.Location,InvoiceSet.InvoiceNumber,InvoiceSet.Amount,InvoiceSet.TotalDiscount,InvoiceSet.GST,
Paid=(InvoiceSet.InvoiceStatusID==2 ? "Paid":"UnPaid"),
datePaid=(InvoiceSet.PaymentDate),InvoiceSet.PaymentDate//,miDate
};
In query I have commented what I want to add as well as commented in Select. From BookedArea table I want to get Minimum Leased Date for every invoiceID.
I just have started using LINQ so dont know how to do this.
Please guide me.
Thanks
Try this:
var selectedResults=
from InvoiceSet in Invoices
join BookedAreaSet in BookedAreas on InvoiceSet.InvoiceID equals BookedAreaSet.InvoiceID
join AreaSet in Areas on BookedAreaSet.AreaID equals AreaSet.AreaID
join ContactSet in Contacts on InvoiceSet.ContactID equals ContactSet.ContactID
join Contacts_ObjectsSet in Contacts_Objects on ContactSet.ContactID equals Contacts_ObjectsSet.ContactID
join CompanySet in Companies on Contacts_ObjectsSet.ObjectReferenceID equals CompanySet.CompanyID
join Customer_CustomerGroupSet in Customer_CustomerGroup on Contacts_ObjectsSet.ObjectReferenceID equals Customer_CustomerGroupSet.CustomerID
join CustomerGroupDiscountsSet in CustomerGroupDiscounts on Customer_CustomerGroupSet.CustomerGroupID equals CustomerGroupDiscountsSet.ID
join InvoiceStatusSet in InvoiceStatus on InvoiceSet.InvoiceStatusID equals InvoiceStatusSet.ID
where Contacts_ObjectsSet.ObjectReference == "Company"
join BookedAreaSet2 in BookedAreas on InvoiceSet.InvoiceID equals BookedAreaSet.InvoiceID into BookedAreas2
let minDate = BookedAreas2.Select(ba2 => ba2.LeasedDate).Min()
select new
{
licensee = CompanySet.CompanyName,
CustomerGroupDiscountsSet.CustomerGroup,
AreaSet.Location,
InvoiceSet.InvoiceNumber,
InvoiceSet.Amount,
InvoiceSet.TotalDiscount,
InvoiceSet.GST,
Paid = InvoiceSet.InvoiceStatusID == 2 ? "Paid" : "UnPaid",
datePaid = InvoiceSet.PaymentDate,
InvoiceSet.PaymentDate,
minDate,
};
I have an application that successfully utilizes LINQ to perform LEFT OUTER JOINs several instances; however, in one case it fails to work as expected.
Testing in LINQPad (using LINQ-to_SQL) produced the correct result; however, to be sure I changed to the LINQPad beta version 4.42.05 and successfully connected using my application's DLL and the connectionString from its web.config file (as per the Add Connection dialog). Again, LINQPad is successful in returning the proper result and clearly generates the expected left outer join in TSQL but the same code in the application fails.
In debugging the function, I get the "Object reference not set to an instance of an object." error. Please see additional descriptions after the following code and related TSQL. Note the relationship involves customer who have one-or-more stores and whoes stores have zero-or-more departments. Therefore, some returned records will not have a department (hence the requirement for the left outer join).
The following code works perfectly in LINQPad:
var model = (from h in SalesOrderHeaders
join c in Customers on h.CustomerId equals c.CustomerId
join s in Stores on h.StoreId equals s.StoreId
join d in Departments on h.DepartmentId equals d.DepartmentId into outer
from o in outer.DefaultIfEmpty()
select new
{
OrderId = h.SalesOrderHeaderId,
OrderDetailId = 1,
SalesOrderDate = h.SalesOrderDate,
DeliveryDateTime = h.DeliveryDateTime,
Customer = c.Customer,
Store = s.Store,
Department = (o.Department == null) ? "None" : o.Department,
FullDescription = "None",
Qty = 0,
UoM = "None",
}).OrderBy (m => m.OrderId);
When the code below is used in the application it fails:
var model = from h in headers
join c in customers on h.CustomerId equals c.CustomerId
join s in stores on h.StoreId equals s.StoreId
join d in departments on h.DepartmentId equals d.DepartmentId into outer
from o in outer.DefaultIfEmpty()
select new SalesOrderGridViewModel
{
OrderId = h.SalesOrderHeaderId,
OrderDetailId = 1,
SalesOrderDate = h.SalesOrderDate,
DeliveryDateTime = h.DeliveryDateTime,
Customer = c.Name,
Store = s.Name,
Department = (o.Name == null) ? "None" : o.Name,
FullDescription = "None",
Qty = 0,
UoM = "None",
};
However, when I change the code in the application so that the boolean in the assignment of the department field of the result references the join element from the headers variable (h.DepartmentId == null) as in the following code:
var model = from h in headers
join c in customers on h.CustomerId equals c.CustomerId
join s in stores on h.StoreId equals s.StoreId
join d in departments on h.DepartmentId equals d.DepartmentId into outer
from o in outer.DefaultIfEmpty()
select new SalesOrderGridViewModel
{
OrderId = h.SalesOrderHeaderId,
OrderDetailId = 1,
SalesOrderDate = h.SalesOrderDate,
DeliveryDateTime = h.DeliveryDateTime,
Customer = c.Name,
Store = s.Name,
Department = (h.DepartmentId == null) ? "None" : o.Name,
FullDescription = "None",
Qty = 0,
UoM = "None",
};
The expected result is returned.
Interestingly the subtle difference in the TSQL generated first from the original code:
SELECT [t4].[SalesOrderHeaderId] AS [OrderId], [t4].[SalesOrderDate],
[t4].[DeliveryDateTime], [t4].[Customer], [t4].[Store],
[t4].[value] AS [Department]
FROM (
SELECT [t0].[SalesOrderHeaderId], [t0].[SalesOrderDate],
[t0].[DeliveryDateTime], [t1].[Customer], [t2].[Store],
(CASE
WHEN [t3].[Department] IS NOT NULL THEN [t3].[Department]
ELSE CONVERT(NVarChar(50),#p0)
END) AS [value]
FROM [SalesOrderHeaders] AS [t0]
INNER JOIN [Customers] AS [t1] ON [t0].[CustomerId] = [t1].[CustomerId]
INNER JOIN [Stores] AS [t2] ON [t0].[StoreId] = ([t2].[StoreId])
LEFT OUTER JOIN [Departments] AS [t3]
ON [t0].[DepartmentId] = ([t3].[DepartmentId])) AS [t4]
ORDER BY [t4].[SalesOrderHeaderId]
And here from the revised code, where the boolean was changed to test the value of the DepartmentId in the original headers table ([t3].[Department] versus [t0].[DepartmentId] ), appears to be the solution:
SELECT [t4].[SalesOrderHeaderId] AS [OrderId], [t4].[SalesOrderDate],
[t4].[DeliveryDateTime], [t4].[Customer], [t4].[Store],
[t4].[value] AS [Department]
FROM (
SELECT [t0].[SalesOrderHeaderId], [t0].[SalesOrderDate],
[t0].[DeliveryDateTime], [t1].[Customer], [t2].[Store],
(CASE
WHEN [t0].[DepartmentId] IS NOT NULL THEN [t3].[Department]
ELSE CONVERT(NVarChar(50),#p0)
END) AS [value]
FROM [SalesOrderHeaders] AS [t0]
INNER JOIN [Customers] AS [t1] ON [t0].[CustomerId] = [t1].[CustomerId]
INNER JOIN [Stores] AS [t2] ON [t0].[StoreId] = ([t2].[StoreId])
LEFT OUTER JOIN [Departments] AS [t3]
ON [t0].[DepartmentId] = ([t3].[DepartmentId])) AS [t4]
ORDER BY [t4].[SalesOrderHeaderId]
While I have found a way to make this work; because it works both ways in LINQPad and successfully in numerous other LINQ queries scattered throughout my application, its failure in the original form in this one location gives me concern.
Ultimately, it appears to fail in the application when I test the returned value of the left outer join. However, this is the documented practice in many books and articles. So my final question is does anyone have any insight into why this would occur and/or how it can work in LINQPad (using the applications DLL and against the same DB)?
This is a classic example of how not to write LINQ queries - thinking in SQL and then transliterating into LINQ.
With LINQ, you can avoid the joins completely and formulate your query as follows:
from h in SalesOrderHeaders
orderby h.OrderId
select new
{
OrderId = h.SalesOrderHeaderId,
OrderDetailId = 1,
SalesOrderDate = h.SalesOrderDate,
DeliveryDateTime = h.DeliveryDateTime,
c.Customer.Customer,
s.Store.Store,
Department = (h.Department == null) ? "None" : h.Department.Department,
FullDescription = "None",
Qty = 0,
UoM = "None"
}
It appears that [t0].DepartmentID (from SalesOrderHeaders) can be null. Your LEFT OUTER JOIN relies on this value. This ends up comparing [t3].DepartmentID to null (in some cases).
You might need to use your CASE statement from the select in the JOIN as well.
I have this LINQ query and I need to make a second Join to it:
var linqQuery = (from r in gServiceContext.CreateQuery("opportunity")
join c in gServiceContext.CreateQuery("contact") on ((EntityReference)r["new_contact"]).Id equals c["contactid"] into opp
from o in opp.DefaultIfEmpty()
where ((EntityReference)r["new_channelpartner"]).Id.Equals(lProfileProperty.PropertyValue) && ((OptionSetValue)r["new_leadstatus"]).Equals("100000002")
select new
But I need to also Join this:
from r in gServiceContext.CreateQuery("annotation")
join c in gServiceContext.CreateQuery("opportunity") on ((EntityReference)r["objectid"]).Id equals c["opportunityid"]
Sorry, I'm sure this is easy. I suck at LINQ though. Any help would be great.
Thanks!
It's not really clear what you mean, but I suggest you want:
var linqQuery = from r in gServiceContext.CreateQuery("opportunity")
where ...
join c in gServiceContext.CreateQuery("contact")
on ((EntityReference)r["new_contact"]).Id
equals c["contactid"] into opp
from o in opp.DefaultIfEmpty()
join r in gServiceContext.CreateQuery("annotation")
on c["opportunityid"]
equals ((EntityReference)r["objectid"]).Id
select new...
It's not clear why you have to cast to EntityReference everywhere and access fields via their names as strings, by the way. Are you sure you can't use something like:
var linqQuery = from opportunity in gServiceContext.Opportunities
where opportunity.ChannelPartner.Id == targetChannelPartner
&& opportunity.NewLeadStatus == 100000002
join contact in gServiceContext.Contacts
on opportunity.Id equals contact.Id into contacts
from contactOrNull in contacts.DefaultIfEmpty()
join annotation in gServiceContext.Annotations
on annotation.ObjectId equals opportunity.OpportunityId
select ...;