I have this SQL query:
SELECT TOP 1 r.* FROM dbo.Request r
LEFT JOIN dbo.Process p
ON r.IdReq = p.IdReq
WHERE IdProcess Is NULL
ORDER BY r.ReqDate ASC
I want write it in a vb.net procedure, using Linq To SQL syntax:
Private Function getOldestRequest() As Request
Dim dc As ProcessDataContext = new ProcessDataContext(ConfigurationManager.ConnectionStrings("...").ConnectionString);
Dim pr = From r In dc.Request
From p In dc.Process.Where(Function(v) v.IdReq = r.IdReq And v.idProcess Is Nothing)
Select New {Request = r}
Return pr
End Function
This is what I wrote, but I get error, on the Return line.
LINQ statements return IEnumerable objects, and your method is returning a single Request object. In your case looks like you only need to return the first result of the LINQ statement.
Something like:
Dim pr = (From r In dc.Request
From p In dc.Process.Where(Function(v) v.IdReq = r.IdReq And v.idProcess Is Nothing)
Select New {Request = r}).FirstOfDefault
Return pr
Change your Select to
Select r
And your return to
Return pr.OrderBy(Function(v) v.RecDate).FirstOrDefault
Related
I've got 2 datatables and am trying to summarize the data in them using a left outer join. The join works fine with this code
Dim Journal = From entries In dt.AsEnumerable()
Join inccodes In dtGL.AsEnumerable()
On entries.Field(Of String)("GLCode") Equals inccodes.Field(Of String)("GLCode")
Group By keys = New With {Key .IncomeCode = entries.Field(Of String)("GLCode"), Key .IncomeDesc = .inccodes.Field(Of String)("GLCodeDesc")}
Into ChargeSum = Group, sm = Sum(entries.Field(Of Decimal)("Amount"))
Where sm <> 0
Select New GL_Journal With {.IncomeCode = keys.IncomeCode, .IncomeDesc = keys.IncomeDesc, .LineAmount = sm}
`
However, since I really want a Left Outer Join I want to use Group Join instead of Join.
As soon as I change the Join to Group Join the code in the Group by at ".inccodes.field(Of String)("GLCodeDesc")" has ".inccodes" highlighted with the error "'inccodes' is not a member of 'anonymous type'"
I've reviewed much documentation on Group By and Group Join but there is scant information on them together.
Any ideas? Would I have more options/success with the method syntax?
If i try to reproduce your query using a left outer join, I will do something like this :
Dim dt As New DataTable
dt.Columns.Add("GLCode", GetType(String))
dt.Columns.Add("Amount", GetType(Decimal))
dt.Rows.Add("111", 3251.21)
dt.Rows.Add("222", 125.79)
dt.Rows.Add("999", 10000)
Dim dtGL As New DataTable
dtGL.Columns.Add("GLCode", GetType(String))
dtGL.Columns.Add("GLCodeDesc", GetType(String))
dtGL.Rows.Add("111", "a")
dtGL.Rows.Add("222", "b")
dtGL.Rows.Add("333", "c")
Dim Journal = From entries In dt.AsEnumerable()
Group Join inccodes In dtGL.AsEnumerable()
On entries.Field(Of String)("GLCode") Equals inccodes.Field(Of String)("GLCode")
Into Group
From lj In Group.DefaultIfEmpty()
Group By keys = New With {Key .IncomeCode = entries.Field(Of String)("GLCode"), Key .IncomeDesc = lj?.Field(Of String)("GLCodeDesc")}
Into ChargeSum = Group, sm = Sum(entries.Field(Of Decimal)("Amount"))
Select New With {.IncomeCode = keys.IncomeCode, .IncomeDesc = keys.IncomeDesc, .LineAmount = sm}
Dim ID_Section as Int32 = 10
Dim Query = From Book1 In db.Book1
Group Join Section In db.Section On CInt(Book1.ID_Section) Equals Section.ID_section _
And Section.ID_section Equals (ID_Section) Into Section_join = Group
From Section In Section_join.DefaultIfEmpty()
Select
Book1.ID_Book,
Book1.Name_Book,
ID_section = Section.ID_section,
Name_Section = Section.Name_Section
The error appears in the variable id_Section, since the Linq does not accept values from the outside, as it seems to me of course.
Here Error :
And Section.ID_section Equals (ID_Section)
In SQL Query Use At :
Declare #ID_Section int
SELECT Book.ID_Book, Book.Name_Book, Section.ID_section, Section.Name_Section
FROM Book LEFT OUTER JOIN
Section ON Book.ID_Section = Section.ID_section and Section.ID_section = #ID_Section
where Book.ID_Book =1
Using Where on db.Section with lambda syntax:
Dim Query = From Book1 In db.Book1
Group Join Section In db.Section.Where(Function(s) s.ID_section = ID_Section)
On CInt(Book1.ID_Section) Equals Section.ID_section _
Into Section_join = Group
From Section In Section_join.DefaultIfEmpty()
Select
Book1.ID_Book,
Book1.Name_Book,
ID_section = Section.ID_section,
Name_Section = Section.Name_Section
Alternatively you can apply the Where to the Join results:
Dim Query = From Book1 In db.Book1
Group Join Section In db.Section
On CInt(Book1.ID_Section) Equals Section.ID_section _
Into Section_join = Group
From Section In Section_join.Where(Function(s) s.ID_section = ID_Section).DefaultIfEmpty()
Select
Book1.ID_Book,
Book1.Name_Book,
ID_section = Section.ID_section,
Name_Section = Section.Name_Section
Please refer to my following code. An exception error occurs at the return value.
Unable to cast object of type 'System.Data.Objects.ObjectQuery1[VB$AnonymousType_23[System.String,System.String,System.String]]' to type 'System.Collections.Generic.List`1[MyEntities.stk_cust]'.
Public Function GetCustomerProdListToGrid() As List(Of stk_cust)
Dim result = From s In Db.stk_cust
Group Join d In Db.s_armaster On d.dbcode Equals s.dbcode Into stk_ar = Group
From d In stk_ar.DefaultIfEmpty()
Order By s.stk_code, s.dbcode Ascending
Select s.stk_code, s.dbcode, d.name
Return result
End Function
I've tried the following method at select section but error turns out the same
Select New With {.stk_code = s.stk_code,
.dbcode = s.dbcode,
.name = d.name
}
Any help is highly appreciated.
If you want to return a List(Of stk_cust) you need to create instances of stk_cust instead of using an anonymous type. Presuming that those are the properties:
....
Select New stk_cust() With {
.stk_code = s.stk_code,
.dbcode = s.dbcode,
.name = d.name
}
Return result.ToList()
Maybe you could also select the object directly without needing to create a new one:
Dim result = From s In Db.stk_cust
Group Join d In Db.s_armaster On d.dbcode Equals s.dbcode Into stk_ar = Group
From d In stk_ar.DefaultIfEmpty()
Order By s.stk_code, s.dbcode Ascending
Select s
Return result.ToList()
I am trying to convert this query:
select sales.TTL_Sales_Net, sales.TTL_Sales_Target, units.TTL_Units_Net
from epos_Anal_Branch_Sales_Day sales
join epos_PULL_PM_SKU_STATUS till on sales.BRANCH_ID = till.BRANCH_ID
join epos_Anal_Branch_Units_Day units on sales.BRANCH_ID = units.BRANCH_ID
where till.BRANCH_ID = 45 and sales.DATEKEY = 20140725 and units.DATEKEY = 20140725
from SQL into an Entity Framework query in VB.net. I am sending in the BRANCH_ID in my function and producing the datekey like so:
Dim MyDate As String = Date.Now.ToString("yyyyMMdd")
This is what I have but it just returns no results and I am at a complete loss as to why! This is my query thus far, if anyone can spot what I have done wrong then I would be grateful for a push in the right direction
Public Class clsStoreSales
Public Property DailyAmount As String
Public Property DailyUnits As String
Public Property SalesTarget As String
Public Property ErrorMessages As String
Public Shared Function GetStoreSales(ByVal BranchID As String) As List(Of clsStoreSales)
Dim live As New RMISEntitiesLive
Dim MyDate As String = Date.Now.ToString("yyyyMMdd")
Dim l As New List(Of clsStoreSales)
Try
Dim r = From till In live.epos_PULL_PM_SKU_STATUS
Join sales In live.epos_Anal_Branch_Sales_Day On till.BRANCH_ID Equals sales.BRANCH_ID
Join units In live.epos_Anal_Branch_Units_Day On till.BRANCH_ID Equals units.DATEKEY
Where till.BRANCH_ID = CDbl(BranchID) AndAlso sales.DATEKEY = CDbl(MyDate) AndAlso units.DATEKEY = CDbl(MyDate)
Select New With {.SalesAmount = sales.TTL_Sales_Net, .SalesTarget = sales.TTL_Sales_Target, .SaleUnits = units.TTL_Units_Net}
For Each t In r
Dim m As New clsStoreSales
m.DailyAmount = CStr(t.SalesAmount)
m.DailyUnits = CStr(t.SaleUnits)
m.SalesTarget = CStr(t.SalesTarget)
l.Add(m)
Next
Return l
Catch ex As Exception
Dim e As New clsStoreSales
e.ErrorMessages = ex.ToString
l.Add(e)
Return l
End Try
End Function
End Class
This is what sqlServer Profiler is showing as the query being run:
exec sp_executesql N'SELECT
[Extent1].[BRANCH_ID] AS [BRANCH_ID],
[Extent2].[TTL_Sales_Net] AS [TTL_Sales_Net],
[Extent2].[TTL_Sales_Target] AS [TTL_Sales_Target],
[Extent3].[TTL_Units_Net] AS [TTL_Units_Net]
FROM [dbo].[epos_PULL_PM_SKU_STATUS] AS [Extent1]
INNER JOIN [dbo].[epos_Anal_Branch_Sales_Day] AS [Extent2] ON [Extent1].[BRANCH_ID] = [Extent2].[BRANCH_ID]
INNER JOIN [dbo].[epos_Anal_Branch_Units_Day] AS [Extent3] ON [Extent1].[BRANCH_ID] = [Extent3].[DATEKEY]
WHERE ( CAST( [Extent1].[BRANCH_ID] AS float) = #p__linq__0) AND ( CAST( [Extent2].[DATEKEY] AS float) = #p__linq__1) AND ( CAST( [Extent3].[DATEKEY] AS float) = #p__linq__2)',N'#p__linq__0 float,#p__linq__1 float,#p__linq__2 float',#p__linq__0=45,#p__linq__1=20140725,#p__linq__2=20140725
This
Join units In live.epos_Anal_Branch_Units_Day On till.BRANCH_ID Equals units.DATEKEY
Should be this!
Join units In live.epos_Anal_Branch_Units_Day On till.BRANCH_ID Equals units.BRANCH_ID
How can I convert an object of type System.Data.Linq.DataQuery to System.Linq.IQueryable?
I'm working with Visual Basic/Silverlight, and the source code of my query is as follows:
Public Function Get_Cli_Pag() As IQueryable(Of V_Cliente_Pagare)
Dim Qry = From P In Me.Context.Pagares Join C In Me.Context.Codigos On C.Codigo
Equals P.Tipo_Pagare Where P.Nulo = 0 And P.Extraviado = 0 And C.Clave = 5 Select P.Rut, P.Cliente.Nombre, P.Tipo_Pagare, Tipo_Pagare_Descripcion = C.Descripcion, P.Pagare
Return Qry.AsQueryable
End Function
Does the .AsQueryable extension method work?