Put Two Linq Query Results Together?
Sep 11, 2009I have used linq quite abit but was just wondering how to append the results of two IEnumerable(of X) together into one IEnumerable(of X)
View 4 RepliesI have used linq quite abit but was just wondering how to append the results of two IEnumerable(of X) together into one IEnumerable(of X)
View 4 RepliesI have a query using LINQ-to-SQL. It queries an underlying database table Rooms. It uses Where conditions to narrow down the results, namely:
Gender.Current Occupancy < Max Occupancy Available Flag is Checked I know this should return results but it keeps returning an empty set.Code is below
[code]...
UPDATE: I've verified that the issue is with the statement where sh.is_available = 1, which doesn't make sense since this is a bit field.
I'm doing some XLINQ in VB for work. I basically need to pull some values from a small chunk of XML as listed here:
<?xml version="1.0" encoding="utf-8"?>
<Fields>
<typeQtyRadioButtonList>1</typeQtyRadioButtonList>
<cmbQtyCheck>Reject</cmbQtyCheck>
[code]....
... Leaving out the implementation of the For Each loop....So I have stuck a break point on the for each and the collection has no elements in it.
I have the following code:
Dim db As New linqclassesDataContext
Dim categories = (From c In db.faq_cats)
NewFaqDropDownCategory.DataSource = categories
[code]....
In my application, I have a search query textbox (txtSearch) that works well with one-word queries with the following LINQ:[code]So how would I make the above query more generic (ie: able to handle any number of words in a query)?I should note that the object being queried is a List of strings pulled from an Access database. As it stands, this application only queries the database once and I'd like to keep it that way if possible.
View 3 RepliesThe only way I know of is awkward:
'check for empty return
Dim count As Integer = (From s In myEntity.employee Where employeeID = myEmployeeIDVariable).Count
'If there is a record, then process
[code]....
I have a VB .Net linq query that I want to return values from two tables. I currently have this:
Dim query = (From c In db.Client _
Join u In db.Users _
On u.UserID Equals c.UserID _
Where (c.ClientID = 1)
Select c, u).ToList
query (System.Collections.Generic.List(Of )) returns several rows as expected each item containing a c and a u.
How do I iterate through the queries collection?
I have the following LINQ-to-Entities query:[code]This will give me all the resident assignments for the current year/term. Then I have this LINQ-to-Entities query:[code]This will give me all the rooms. I want to iterate through the assignments and based on what room is assigned update the occupancy in reset_occupancy. I'm not 100% sure how to accomplish this. Here is my pseudo code of what I want to accomplish:[code]
View 1 RepliesI have the following LINQ-to-Entities query:
' Get all the residency assignments that match the term/year.
Dim assignments = From p In dbContext.Residents _
Where p.semester = term _
[code].....
I 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.
how to take a query that returns a single row of data and load that data into textbox controls.I know about ExecuteScalar but it is only good for a single column of data from the query.
View 2 Repliesgiven 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
if there is that much of a performance gain in running a LINQ stored procedure versus a LINQ query?
View 1 RepliesI 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]....
Forgive 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."
Ok i have a query i use to parse an xml file to get an id number of a movie that allows me to get more detailed information about that movie from a database.Now the problem is the id is returned correctly with xml files stored on my hard drive (c:\desktop\movies)but when i try and parse an xml file on an external drive it dont get a hit on the <id>1123</id> node.
query
Function movieID(ByVal directory)
'Get the movie name
[code].....
I've got some code to try and loop through LINQ results, but it doesn't seem to be working.
HERE'S THE CODE
Public Sub ProcessRequest(ByVal context As System.Web.HttpContext) Implements System.Web.IHttpHandler.ProcessRequest
''# the page contenttype is plain text'
[Code]....
I have setup an OleDbConnection and my query works just fine but the problem I am facing is that I want the entire query not just a certain row or column. I also would like to place this entire query into a blank excel spread sheet.[code]
View 1 RepliesBefore LINQ I would have my main application return the results of a SQL query into a dataSet. I would then transfer the dataset as a parameter to the external dll. Now I am bringing through a LINQ to SQL query that is returned as an IQueryable(Of vClientTable) object. I want to be able to transfer that set of vClientTable results to my external dll in order for the dll to work with the data included in the results.
I am probably doing it all wrong as well as trying to do it all wrong, but would like some advice on what would be the best method to use.
DB Query
Public Shared Function getClientData(ByVal clientID As Int32) As IQueryable(Of vClientTable)
Try
Dim r = From p In dbLINQ.vClientTable _
[Code]....
Obviously in the external dll it has no idea what an IQueryable(vClientData) object is and even if I create a dbml file and datacontext in my external project for the dll that includes the same class to the DB table/view it still says that the objects are different types.
Just when I was thinking that I had Linq To Xml sussed I'm faced with yet another error! I think if I was to understand the linq search process in general better I might have more success, so any good links regarding that are also welcome. To my problem however; using the code below:
[Code]...
I'm having trouble populating an object from an XML file. I've copied an example I've found almost exactly, with variable names changed, but I keep getting the "Enumeration yielded no results" exception.
Here is my code:
[code]...
Essentially, the XML query is supposed to return the title and the description for every Property which has an element called Language Code, which is equal to "en-us". I have a feeling that my problem lies in my XML code, but I've been stuck here for a long time now.
I'm trying to return a single object from an array of objects with linq.[code]...
View 2 RepliesSo, I'm not really sure if I have this setup properly or not. This is my first attempt at utilizing LINQ and I am trying to return data directly from an XML file.Here is my XML structure:
<folder_list>
<folder lbl="_localhost" abs="C:\_localhostapache2triadhtdocs" unc="C:\_localhostapache2triadhtdocs" tag="default" />
<folder lbl="Programming" abs="D:\_prog" unc="D:\_prog" tag="default" />
<folder lbl="Anime" abs="D:Anime" unc="D:Anime" tag="default" />
[Code]...
We 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]....
How 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.
If this is in the wrong section, I have a program that queries a database and puts the info in a specific format in a txt file. Now my problem comes w/ how to format the date.
Should I format the date in the SQL query OR is there a way to take the result from the query and format sometime before it is writen to the txt file? I'm not exactly sure how to do either. Would I need a subquery to get the desired date format?
[Code]...
I am using an access DB and wanted to create a query that returns user's in the db. First I need to check the db to see if it is empty. Then I need to check to see it my query returned any values. How do I go about doing this?
View 6 RepliesI'm a bit confused on how to grab query results. With VBA i would open a record set and have the results of the query written to that recordset. IN VB.net how can I grab the query result and throw each column into specfic arrays?[code]Now how would I force it to query my DB? I have a connection established already.After the query how can i play with the columnes and place them into arrays?
View 2 RepliesI had this query sp_msforeachdb 'select "?" AS db, * from [?].sys.tables' when I execute it in sql server, it return multiple results. How I can read all the results in my vb?
View 2 RepliesI have the following code in my program: Dim empenrollments = From enroll In db.EnrollmentSummary(eid)
Select New With {.Name = ename, enroll} Dim elist = empenrollments.ToList returns this error
In the following lines, I have to get each row in the returned results and add it to a DataTable, but it never gets there.
[Code]...