我正在尝试在linq中执行左连接到具有date1>的sql; date2比较,但无法弄清楚如何。这是SQL:
select
rd.RouteDispatchID,
r.RouteNumber,
s.ShortDescription,
rd.DispatchDate,
rd.CreationDate,
e.FirstName,
e.LastName,
count(md.MachineDispatchID) NumMachines,
count(mdp.Pick) TotalPicks,
sum(mh.BillsToStacker) + sum(mh.BoxCash) TotalCash,
sum(mh.TubeCash) - sum(mh.CashOut) NetCoinsToTubes
from dbo.RouteDispatch rd
inner join dbo.Route r on rd.RouteID = r.RouteID
inner join dbo.Reference s on rd.StatusCodeReferenceID = s.ReferenceID
inner join dbo.Employee e on rd.CreatedByEmployeeID = e.EmployeeID
left join dbo.MachineDispatch md on rd.RouteDispatchID = md.RouteDispatchID and md.IsSelected = 1
left join dbo.MachineDispatchPick mdp on md.MachineDispatchID = mdp.MachineDispatchID
**left join dbo.MachineHistory mh on md.MachineID = mh.MachineID and mh.ReadDate > m.LastServiceDate**
group by rd.RouteDispatchID,
r.RouteNumber,
s.ShortDescription,
rd.DispatchDate,
rd.CreationDate,
e.FirstName,
e.LastName
我把左边的连接以粗体显示。到目前为止,这是我对linq的所有内容,但是我遗漏了mh.ReadDate> m.LastServiceDate,因为我不知道该怎么做:
var query = from rd in db.RouteDispatches
join r in db.Routes on rd.RouteID equals r.RouteID
join s in db.References on new { StatusCodeReferenceID = rd.StatusCodeReferenceID } equals new { StatusCodeReferenceID = s.ReferenceID }
join e in db.Employees on new { CreatedByEmployeeID = rd.CreatedByEmployeeID } equals new { CreatedByEmployeeID = e.EmployeeID }
join md in db.MachineDispatches
on new { rd.RouteDispatchID, IsSelected = true }
equals new { md.RouteDispatchID, IsSelected = md.IsSelected.Value } into md_join
from md in md_join.DefaultIfEmpty()
join mdp in db.MachineDispatchPicks on md.MachineDispatchID equals mdp.MachineDispatchID into mdp_join
from mdp in mdp_join.DefaultIfEmpty()
join mh in db.MachineHistories on md.MachineID equals mh.MachineID into mh_join
from mh in mh_join.DefaultIfEmpty()
group new { rd, r, s, e, md, mdp, mh } by new
{
rd.RouteDispatchID,
r.RouteNumber,
s.ShortDescription,
rd.DispatchDate,
rd.CreationDate,
e.FirstName,
e.LastName
} into g
select new RouteView
{
RouteDispatchID = g.Key.RouteDispatchID,
RouteNumber = g.Key.RouteNumber,
Status = g.Key.ShortDescription,
DispatchDate = g.Key.DispatchDate.Value,
CreatedDate = g.Key.CreationDate.Value,
FirstName = g.Key.FirstName,
LastName = g.Key.LastName,
NumMachines = g.Count(),
TotalPicks = g.Count(),
TotalCash = (g.Sum(p => p.mh.BillsToStacker.Value) + g.Sum(p => p.mh.BoxCash.Value)),
NetCoinsToTubes = (g.Sum(p => p.mh.TubeCash.Value) - g.Sum(p => p.mh.CashOut.Value))
};
任何人都知道如何让它发挥作用?
答案 0 :(得分:0)
我在Linqer中加载了你的查询,当我尝试转换它时,我收到了这个错误:
SQL无法转换为LINQ:只能使用JOIN表达式中的“=”运算符。 “>” 中运算符无法转换。
所以我将违规标准移到了where子句。然后我能够毫无问题地进行转换。以下是结果。
from rd in db.RouteDispatch
join r in db.Route on rd.RouteID equals r.RouteID
join s in db.Reference on new { StatusCodeReferenceID = rd.StatusCodeReferenceID } equals new { StatusCodeReferenceID = s.ReferenceID }
join e in db.Employee on new { CreatedByEmployeeID = rd.CreatedByEmployeeID } equals new { CreatedByEmployeeID = e.EmployeeID }
join md in db.MachineDispatch
on new { rd.RouteDispatchID, IsSelected = true }
equals new { md.RouteDispatchID, md.IsSelected } into md_join
from md in md_join.DefaultIfEmpty()
join mdp in db.MachineDispatchPick on new { MachineDispatchID = md.MachineDispatchID } equals new { MachineDispatchID = Convert.ToString(mdp.MachineDispatchID) } into mdp_join
from mdp in mdp_join.DefaultIfEmpty()
join mh in db.MachineHistory on md.MachineID equals mh.MachineID into mh_join
from mh in mh_join.DefaultIfEmpty()
group new {rd, r, s, e, mh} by new {
rd.RouteDispatchID,
r.RouteNumber,
s.ShortDescription,
rd.DispatchDate,
rd.CreationDate,
e.FirstName,
e.LastName
} into g
select new {
RouteDispatchID = (System.Int32?)g.Key.RouteDispatchID,
RouteNumber = (System.Int32?)g.Key.RouteNumber,
g.Key.ShortDescription,
DispatchDate = (System.DateTime?)g.Key.DispatchDate,
CreationDate = (System.DateTime?)g.Key.CreationDate,
g.Key.FirstName,
g.Key.LastName,
NumMachines = (Int64?)g.Count(),
TotalPicks = (Int64?)g.Count(),
TotalCash = (System.Int32?)(g.Sum(p => p.mh.BillsToStacker) + g.Sum(p => p.mh.BoxCash)),
NetCoinsToTubes = (System.Int32?)(g.Sum(p => p.mh.TubeCash) - g.Sum(p => p.mh.CashOut))
}
答案 1 :(得分:0)
from rd in dc.RouteDispatches
join r in dc.Routes on rd.RouteID equals r.RouteID
join s in dc.References on rd.StatusCodeReferenceID equals s.ReferenceID
join e in dc.Employees on rd.CreatedByEmployeeID equals e.EmployeeID
from md in (
from md in dc.MachineDispatches
where md.RouteDispatchID == rd.RouteDispatchID
&& md.IsSelected == 1
select md
).DefaultIfEmpty()
from mdp in (
from mdp in dc.MachineDispatchPicks
where mdp.MachineDispatchID == md.MachineDispatchID
select mdp
).DefaultIfEmpty()
from mh in (
from mh in dc.MachineHistories
where mh.MachineID == md.MachineID
&& mh.ReadDate > m.LastServiceDate
select mh
).DefaultIfEmpty()
group .... etc...