Joning tables after group by on one table using T SQL/ LINQ - sql-server

Question

I have two tables:
db.EmployeeReason
db.employee
with following fields:
CREATE TABLE [dbo].[Employee_Reason](
[Id] [int] IDENTITY(1,1) NOT NULL,
[IdEmployee] [int] NOT NULL,
[IdReason] [int] NOT NULL,
[AverageServiceTime] [time](0) NULL,
[Skillset] [bit] NOT NULL,
CONSTRAINT [PK_Employee_Reason] PRIMARY KEY CLUSTERED ([Id] ASC) ON [PRIMARY]
) ON [PRIMARY]
GO
ALTER TABLE [dbo].[Employee_Reason] WITH CHECK ADD CONSTRAINT [FK_Employee_Reason_Employee] FOREIGN KEY([IdEmployee])
REFERENCES [dbo].[Employee] ([Id])
GO
where as the employee table looks like this:
CREATE TABLE [dbo].[Employee](
[Id] [int] IDENTITY(1,1) NOT NULL,
[EmployeeId] [int] NOT NULL,
[FirstName] [nvarchar](20) NOT NULL,
[LastName] [nvarchar](40) NOT NULL,
[IdLocation] [int] NOT NULL,
[IdStatus] [int] NOT NULL,
[UserId] [nvarchar](450) NOT NULL,
[IsArchived] [bit] NULL,
[IdAssignedLocation] [int] NOT NULL,
[IdQueue] [int] NOT NULL,
[IdPosition] [int] NOT NULL,
CONSTRAINT [PK_Employee] PRIMARY KEY CLUSTERED ([Id] ASC) ON [PRIMARY]
) ON [PRIMARY]
I want to group employee_reason by idreason and then join with employee using Employee_Reason.idemployee and employee.id like this:
List<SelfServeReason> skillsetReasons =
from reason in db.EmployeeReason
group reason by IdReason into reasonGroup
join employee in scheduleEmployees on reasonGroup.IdEmployee equals employee.Id
select new skillsetReason
{
id = reasonGroup.Id,
description = reasonGroup.Description,
estimatedWaitTime = min(employee.NextAvailableTime) – ConvertToCST(DateTime.Now)
};
I have written it like this:
select MAX(er.Id)
from Employee_Reason er join Employee e on er.IdEmployee = e.id
group by er.IdReason
but not sure how to group employee_reasons and then join this group with idempoyee.
The linq is not correct, it is just pseudocode, if someone can suggest wha will be correct linq that is helpful as well.
Can you please suggest the solution?

Answer 1

If what you want is a SQL query simmilar to that linq query, then you could do:
select er.IdReason, MIN(e.NextAvailableTime) - GETDATE()
from Employee_Reason er
inner join Employee e on er.IdEmployee = e.id
group by er.IdReason
Also, the correct linq would look like this:
var now = ConvertToCST(DateTime.Now);
List<SelfServeReason> skillsetReasons = (
from employee in scheduleEmployees
join reason in db.EmployeeReason on employee.Id equals reason.IdEmployee
group employee by reason.IdReason into reasonGroup
select new SelfServeReason
{
Id = reasonGroup.Key,
EstimatedWaitTime = reasonGroup.Min(p => p.NextAvailableTime).Subtract(now),
}).ToList();
Just bear in mind that I excluded the selection of Description from the queries, as you provided no such column on any table nor is there a table like Reason with that column on it.
Also, the tables you provided have no such columns as Employee.NextAvailableTime, so I'm assuming you forgot to put them there, seeing that it on your linq query.
And least, you provided no spec for that SelfServeReason class, so I'll just go on with filling it with the columns I know your model have.
If that's not the case, please expand your question with this adjustments and I'll edit my answer.