Linq To SQL Equivalent Of Query
Mar 5, 2012This is the query that I'm trying to reproduce:
[Code]...
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C# Equivalent Of VB LINQ Query?
Jul 20, 2011I have the following query in VB, but I do not know how to translate it to C# synatax
Dim q = From c In db.Customers
Group Join o In db.Orders On c.CustomerID Equals o.CustomerID Into orders = Group
Select New With {c.ContactName, .OrderCount = orders.Count()}
Linq Equivalent On Sql Query ?
Jun 12, 2012Find the Linq equvalent on the below sql query:
select sum(weight) from (
select weight from pers p
join list l on l.persindex= p.persindex
group by p.persindex,weight) a
Equivalent To C# Var Keyword - Retrieve The Result Of A LINQ Query?
Mar 19, 2010Is there a VB.NET equivalent to the C# var keyword? I would like to use it to retrieve the result of a LINQ query.
View 4 RepliesHow To Use The Vb Equivalent Of ++ For An Index Property In A Linq Query Projecting A New Type
May 3, 2011I'd normally do this in C# but since I've got to get this code in this particular assembly which is a vb.net one, I'm stuck.
Here's my linq query:
Dim i As Integer = 0
Dim oldAndCurrentIntersectionOnNames = From currentApplicant In currentApplicants _
Group Join oldApplicant In oldApplicants _
[CODE]...
You'll see the .Index = i+=1
This was my attempt to do what I'd quite happily do in C# (i.e. Index = i++) in VB. Unfortunately the VB compiler doesn't like that. how I'd do this in VB.
LINQ Query Is Enumerated - Turn On Some Kind Of Flag That Alerts Me Each Time A LINQ Query Is Enumerated?
Sep 22, 2009I know that LINQ queries are deferred and only executed when the query is enumerated, but I'm having trouble figuring out exactly when that happens.Certainly in a For Each loop, the query would be enumerated.What's the rule of thumb to follow? I don't want to accidentally enumerate over my query twice if it's a huge result.
For example, does System.Linq.Enumerable.First enumerate over the whole query? I ask for performance reasons. I want to pass a LINQ result set to an ASP.NET MVC view, and I also want to pass the First element separately. Enumerating over the results twice would be painful.It would be great to turn on some kind of flag that alerts me each time a LINQ query is enumerated. That way I could catch scenarios when I accidentally enumerate twice.
.NET Equivalent To This C# Linq Class?
Sep 25, 2009I'm trying to convert something from C# to VB.NET and I'm having trouble finding an equivlent in VB.NET to C#'s yield keyword. I realize 'yield' is not a convertable keyword to VB.NET, so can someone please show me how I would implement this code in VB.NET. I got all of it converted over except for the implemented GetEnumerator() function. It is simply a class that implements CollectionBase and IEnumerable (to make it LINQ worthy):
[Serializable()]
public partial class Customers : CollectionBase, System.Collections.Generic.IEnumerable<BusinessLayer.Customer>
{
[code]....
LINQ Equivalent For SQL Between Keyword?
Feb 12, 2010Is there a LINQ To SQL equivalent to the SQL between keyword?[code]...
View 2 RepliesWhat's The LINQ Equivalent To SUM(CASE WHEN X=Y THEN 1 ELSE 0 END)
Sep 18, 2009Not sure if this is just a bad habit, or a valid way of doing things, but for large complex report queries spanning bunches of tables, I often get my aggregate stats by summing a Case statement.For example:
SELECT Contact.Name,
SUM(CASE WHEN Order.Type = 'Special' THEN 1 ELSE 0 END) AS SpecialOrders,
SUM(CASE WHEN Order.Type = 'Magic' THEN 1 ELSE 0 END) AS MagicOrders,
[code].....
.net - ActiveRecord Linq/NHibernate Linq Not Building Query Completely?
Jul 14, 2011given this function:
Public Function Search(ByVal StartIndex As Integer, _
ByVal MaxResults As Integer, _
ByVal AccountNumber As String, _
ByVal LastName As String, _
[Code]....
instead of what I expected:
Select count(*) from remitline where lastname = "smith"
What am I doing wrong building up the where clause? I'm using Castle ActiveRecord 2.1
Performance Gain In LINQ Query Vs LINQ Stored Procedure?
Aug 6, 2009if there is that much of a performance gain in running a LINQ stored procedure versus a LINQ query?
View 1 RepliesTranslate Obscure LINQ - SQL Equivalent?
Sep 22, 2010Some long-gone developer left the following LINQ query behind with no documentation and I'm struggling to understand what it does (and therefore if it's doing it right), either by breaking it into pieces or providing the SQL equivalent?
CODE:
I am struggling in particular with the Group Join and Into TargetMatches = Group pieces:
CODE:
Asp.net - Complex Linq Query - Add A .Where() Or .Any() Predicate To Reduce Query Complexity (in VB)?
Sep 14, 2010I have to join two main tables, and I need to filter the results by elements in an ASP.NET web form. These filters are created on the fly so I have to use a lot of where extensions to filter the query. I want to execute the query with as optimized SQL as possible.
I am first doing a simple join between TW_Sites and TW_Investigators. Then there are two sub-tables that are involved. TW_InvestigatorToArea and TW_InvestigatorToDisease. While most of the where clauses are working fine, I have found a performance issue that won't be an issue right now, but will be an issue as the table gets bigger.
The arrays DiseaseCategories and DiseaseAreas would be the results of a CheckBoxList result.
Protected Sub LoadResults()
'Get Dictionary of Filters
Dim FilterDictionary As OrderedDictionary = Session.Item("InvestigatorFilterDictionary")
' Initialize LinqToSql
[code]....
LINQ Query Using The Dynamic LINQ Library?
Mar 31, 2011Forgive my ignorance on this.I have this LINQ Query:Dim ngBikersDataContext As New CarBikeWalkDataContext
bikersList = (From c In ngBikersDataContext.Reg_Bikers _
Order By c.L_Name _
Select New Bikers() With { _
.BikerID = c.BikerID, _
.F_Name = c.F_Name, _
[Code]...
with the error "Overload resolution failed because no accesible 'Select' accepts this number of arguments."
Over the "NEW" I get an error " ')'expected."
What's Equivalent Syntax For Anonymous Types In A LINQ Statement
Jun 29, 2010I'm trying to translate some C# LINQ code into VB.NET and am stuck on how to declare an anonymous type in VB.NET.[code]How do you translate C#'s new { ... } syntax into VB.NET?
View 2 RepliesEquivalent To JOIN Query With Dataset Multiple Tables?
Dec 21, 2011How to Query multiple tables in a dataset to form single consolidated table without using any external database. I know this can be done using 'JOIN' in SQl.
Now my condition is I have multiple tables filled with data in a dataset and each table is interrelated with a common 'column'. For example ,
Table 1
ID
Name
1
[Code].....
Here I mentioned only two tables but in my case there are many tables. I need a generic answer for this dynamic query .
"System.ArgumentException: An Item With The Same Key Has Already Been Added." When Trying To Order An In-memory LINQ Query By A LINQ Association?
Jan 27, 2011We are doing a query against an in-memory collection of LINQ data objects. The wrinkle is that we are ordering by a column in a related table whose records have not necessarily been loaded yet (deferred loading:)
Dim oPkgProducts = _
From b In oBillPkg.BillProducts _
Where b.Successful.GetValueOrDefault(Common.X_INDETERMINATE) = _
[code]....
LINQ To SQL - Add In Row_Number To A LINQ To SQL Query?
Aug 31, 2011How do I add ROW_NUMBER to a LINQ query or Entity? How can I convert this solution to VB.NET?
[Code]...
I'm having trouble porting that last line. I have been unable to locate a VB.NET example. I'm actually not looking for any paging functionality like the example provides, just good old-fashioned Row_Number(Order By X) row index.
VS 2008 Linq Possible To Use Query In Another Query?
Apr 16, 2011I was wandering is it possible to use a query within another query below is the code I am trying to use.
Public Function GetInventByComp(ByVal CompID As String) Using DC As New DataClassDataContext
'need to get company id's based off names? thats bad should be name from Id need to rethink this
Dim invent = (From C In DC.Inventors_Companies _
Where C.CompID = CompID _
Select C.InventorID).ToString
[Code]...
I was trying to us multiple values in a string like "1, 3, 5" but I can't seem to get that working either so I am trying to use just a single value now. Can anyone help me? "Yes I am new to this"
.net - Should Use LINQ For This Query
Sep 4, 2009I've been reading a fair bit about the performance of using LINQ rather than using a for each loop and from what I understand using a LINQ query would be a little bit slower but generally worth it for convenience and expressiveness. However I am a bit confused about how much slower it is if you were to use the results of the query in a for loop.
Let's say that I have a set called 'Locations' and a set of objects called 'Items'. Each 'item' can only belong to one 'location'. I want to link items that are under the same location to each other. If I were to do this using a normal 'For Each' loop it would be something like this:
For Each it as Item in Items
If it.Location.equals(Me.Location)
Me.LinkedItems.Add(it)
End If
Next
However if i was to use LINQ it would instead be this:
For Each it as Item in Items.Where(Function(i) i.Location.equals(Me.Location))
Me.LinkedItems.Add(it)
Next
is the second (LINQ) option going to loop once through the entire 'Items' set to complete the query, then loop through the results to add them to the list, resulting in essentially two loops, or will it do the one loop like the first (For Each) option?
Can Do A LINQ Query Of A LINQ Query?
Mar 24, 2012Is it possible to do the following? [code] Basically I have one Load_Gridview function that is called on all postbacks, and rather than creating a bunch of different cases.I want the filters to stack.My actual code has more filters set up (4 or 5 of the).It all compiles ok but when I run and try to execute with active checked, or a department selected I get the following error. [code]
View 4 RepliesLinq Query In .net?
May 5, 2009I have below XML file
<?
xml version="1.0" encoding="utf-8" ?><
PageFlow>
<
attributegroup name="Search"><
attributes>
[Code]...
Put A Sum() In Linq Query?
Apr 18, 2012I am looking to sum the "Status" field.
Dim _detailRecords As New DataTable
_detailRecords.Columns.Add("y")
_detailRecords.Columns.Add("z")
[Code]....
I'm also wanting to keep this as an IEnumerable of DataRow because I will be creating a datatable from it with
Dim yyyyy As DataTable = query8.CopyToDataTable
Query With Linq To Xm?
Aug 13, 2010I am Fairly new to Linq and I am trying to write a simple query to return the error messages within my xml file.
<?xml version="1.0" encoding="utf-8"?>
<Error xmlns="urn:xxxxx">
The following errors were detected:
[code].....
Why The Sql Query Is Different On That Linq Query When Run On C# And On .net
Aug 26, 2009if I run this under c#
from p in Addresses where p.Address2 == null select p.AddressID
it generate this query
SELECT [t0].[AddressID]
FROM [dbo].[Address] AS [t0]
WHERE [t0].[Address2] IS NULL
if I run this under vb.net
from p in Addresses where p.Address2 = nothing select p.AddressID
it generate this query
SELECT [t0].[AddressID]
FROM [dbo].[Address] AS [t0]
WHERE [t0].[Address2] = ''
p.Address2 is a varchar field that accept null value
why vb.net is "wrong" ?
.net - Converting Linq To XML Query From C# To .Net?
Dec 1, 2009I'm converting the Linq query below from C# to VB.Net. Can you spot my error? The query joins 3 XML datasets. C# - This one works great.
List<Course> courses =
(from course in CourseXML.Descendants(ns + "row")
join coursecategory in CourseCategoryXML.Descendants("Table") on (string)course.Attribute("code") equals (string)coursecategory.Element("DATA")
[code]....
.net - Dynamic Linq Query?
Mar 14, 2011I have been trying the following but it returns unexpected results:
Dim xd As XDocument = _
<?xml version="1.0" encoding="utf-8"?>
<root>
[code].....
The above result returns both 'element' nodes however it should only return the first where element/subelement@id=1/subsubelement@id=3 However if results.Ancestors. is used it returns the correct 'subelement' and if that line is not included it returns a single 'subsubelement' whih is also correct I don't understand why when mvoing to the 'element' it returns both (I realise both have a subelement with id=1 but I thought each further query would filter out the presvious results)?
.net - LINQ C# Query In VB - Getting An Error
Feb 22, 2012I have a List of Price Objects (Price contains Date, High, Low) and am trying to extract monthly averages via LINQ. I have this working in C# but we have a few legacy applications that need it in VB.Net and I can't quite seem to figure out the conversion. I've even tried breaking it into two queries to no avail.
[Code]...
.net - Linq Query If Statement?
Jun 24, 2011Ok im trying to do a if statement in Linq and was wondering if it was possible to do something like:
Dim loadFriends = From p In db.UserRelationships Where p.aspnet_User.UserName = User.Identity.Name _
Or p.aspnet_User1.UserName = User.Identity.Name And p.Type = 1 _
Select New With {if p.aspnet_user1.user = "a certan username" then .username = _
p.aspnet_user.username else .username = p.aspnet_user1.Username}
[Code]...
.net - Linq Query To List?
Sep 2, 2011Dim query = From o In myContainer.MyObjects Select o.MyStringProperty Distinct
Dim myProperties As List(Of String) = query.ToList????? 'no way!!!'
"query" type is IEnumerable(Of String)
I tried to use the query directly as a DataSource of a (infragistic) combobox, but it throws me NullReferenceException, so I decided to convert it to a listof strings, to be a more "classical" datasource.
Dim values As List(Of String) = query.AsQueryable().ToList()
does not work either: Value of type 'System.Collections.Generic.List(Of System.Linq.IQueryable(Of String))' cannot be converted to 'System.Collections.Generic.List(Of String)'.