我们如何使用Linq C＃左连接，计数，总和在其中执行选择到另一个选择

Question

How can I convert my sql code into Linq format :

How can we perform a select into another select using Linq c# :

My sql code :

SELECT DepartementProjects.Label, a.Number FROM
(SELECT DepartementProjects.Label ,count(1) as Number FROM DepartementProjects
inner join Absences on DepartementProjects.Id = Absences.DepartementProjectID
where Absences.Profil='SHT'
group by DepartementProjects.Label ) a right join DepartementProjects on DepartementProjects.Label = a.Label;

My attempt :

            var AbsByDepartmentADM = from department in _dbContext.DepartementProjects
                                 join abs in _dbContext.Absences on department.Id equals abs.DepartementProjectID
                                 into groupedResult 
                                 from groupedResultRight in groupedResult.DefaultIfEmpty()
                                 group groupedResultRight by department.Label into grouped
                                 let NumberOfAbsence = grouped.Count(t => t.DepartementProjectID != null)
                                 let WorkedHours = grouped.Sum(a => a.WorkedHours != null ? a.WorkedHours : 0)

                                  select new
                                  {
                                      DepartmentId = grouped.Key,
                                      NumberOfAbsence,
                                      WorkedHours,
                                      AbsencesHours = (8 * NumberOfAbsence - WorkedHours),

                                  };

Answer 1

If you are trying to translate SQL, translate any subselects first, then the main select, and translate in LINQ phrase order. Also, your LINQ adds some values not in the SQL, so I didn't try to change the SQL to match:

var sub = from dept in _dbContext.DepartementProjects
      join abs in _dbContext.Absences on dept.Id equals abs.DepartementProjectID into absj
      from abs in absj
      where abs.Profil == "SHT"
      group abs by dept.Label into absg
      select new { Label = absg.Key, Number = absg.Count() };

var ans = from dept in _dbContext.DepartementProjects
      join a in sub on dept.Label equals a.Label into lnj
      from ln in lnj.DefaultIfEmpty()
      select new { dept.Label, ln.Number };