.net - Linq Concat Column By Val?
Jun 27, 2012I just looking how to use LINQ for grouping a list.
Class Item
Public col1 As String
Public col2 As String
Public col3 As String
Public description As String
[Code]...
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.net - Order By Does Not Work With Concat() In LINQ
Aug 8, 2011Using VB.net and the following LINQ statement. I suspect the "Order by" does not work with Concat(). I want to list the current item the user has and then list more available items in asending order. So first i select the current item from the db and then select the next available items in order. LINQ is ignoring the order by statement and sorting by the PK (which is itemID) I examined the list immediately after executing the statement. When I break up the statement and do them separately they work as predicted.
(From items In myDatabase.ItemAssignments _
Where items.BuildingID = buildingID _
And items.ResidentID = ResidentID _
[Code].....
Concatenation - Concat Strings By & And + In .Net?
Jan 12, 2011Is there any difference between & and + operators while concatenating string?if yes, then what is difference? And if No, then why below code generating exception?
Example:
Dim s, s1, t As String
Dim i As Integer
s1 = "Hello"
[code]....
Concat ComboBox Data - How To Combine Values
Nov 26, 2010How do I concat combo box data. E.g. value in combo box 1 is "L1" and value in combobox 2 is "03". How do I combine them together into L103? Part of the code looks like this. I am trying to combine two combo box values into one single string and save it in my database. I tried to run the program, but when I click the save button, nothing happen. And I look into my database, no data being added.
Dim strInsert, psID As String
psID = cboLevel.Text & cboLNumber.Text
strInsert = "INSERT INTO
[Code] ....
C# - Is It From A Sight Of Resources Reasonable To Use A StringBuilder Already To Concat Two Strings
Jul 9, 2010Is it from a sight of resources reasonable to use a StringBuilder already to concat two strings or is there a minimum concatenation operations that makes the StringBuilder efficient?
View 4 RepliesDynamic Column In Linq?
Jan 5, 2010Dim query=Form f in BBSDb.Forms order by f.FormID Descending Select f where I want the f.FormID to be able to replace with a variable..What I mean is.. it doesn't have to f.FormID .. I may want to set f.FormName to be in descending for example using the code dynamically.. Is there anyway to achive?
View 2 RepliesC# - Give A Specific Name To Column In Linq
Oct 18, 2011I have following query,
[Code]....
how to do it in linq queries ??? also is it possible to combine firstName and lastname in select query in Linq ? just like we do in SQL Queries like : select me_first_name + ' ' + me_last_name as 'Full Name' from me_employee how can i achieve this task in linq?
Find A DataTable Row By Column Value Using LINQ?
Jan 7, 2012I have a Dynamic DataTable Created at runtime. The Setup is like so
Id | Name | Age
-----------------
3 | Mike | 21
6 | John | 43
8 | Sara | 34
What I am trying to do is come up with a linq statement I could use to find and update specific rows.
Such as a statement to change AGE to '33' WHERE ID = '3'
My code So far is:
-[VB.NET]-
Dim MyRow As DataRow = From column In MyTable.Rows Where column("Id") = 3
MyRow(0)("Age") = 33
But this is not updating my DataTable entry.
Getting Column From Joined Subtable In LINQ?
May 24, 2011I dont know how to access the value from a Subtable "Produkt"
I have a datagridview wich uses the Datasource from the LINQ result from the picture.
The columns from Maintable are displayed correctly. But for the Subtable "Produkt" i cant reach the Name Column value. if i Use "Produkt" in the DataPropertyName the Result is: {ContainerDB.tbl_Produkt} with Produkt.Name nothing is displayed.
How To Convert Column In Order By Linq
Sep 21, 2010Same thing I am trying to do in the linq order by. It's not working.I have column that is defined in the data base as string (Varchar) and I need to cast/convert it to integer before I need to sort it.What should be my linq statement?
View 1 RepliesLinq To SQL Walkthrough - Column Name Not Valid
May 16, 2011Giving it a go at LINQ to SQL.
Tools: VB2008 Express to SQL Compact Northwind DB
I am doing the following walkthrough: [URL]. I did the walkthrough step by step although I get the following message ...... The column name is not valid. [ Node name (if any) = t0,Column name = CustomerID ] ....... on the first line of the following code.
' Execute the query.
For Each custObj In custQuery
msg &= String.Format(custObj.CustomerID & vbCrLf)
Next
I have enabled all that the walkthrough indicates but to no avail.
Select More Than One Column In A Linq Query?
Nov 2, 2009Dim MyQuery = From c In xdoc.Descendants() _
Where c.Attribute(OriginY) IsNot Nothing _
Order By Val(c.Attribute(OriginY).Value), Val(c.Attribute(OriginX).Value) _
Select c.Attribute(UniStr)
Right above you can see my First! linq attempt! And here comes my first question.
How can i select more than one column in a linq query in vb.net?
For example... Select c.Attribute(UniStr) AND c.Attribute(OriginY)
Update A Column In A Database Using Linq?
Aug 22, 2009I use this command to retrieve information from an Access database:
Try
Dim result = From row In Me.ChitaDataSet1.chita.AsEnumerable() _
Where row.Field(Of String)("askID") = x _
Select row[code]....
how to Update a cell in specified row-coloumn coordinates?
.net - LINQ Error Type DBNull Column?
Apr 29, 2011I am querying a datagridview and it works great unless one of the cells has nothing (dbnull). How to over come this?Exceptions: Operator '=' is not defined for type 'DBNull' and type 'DBNull'.
Dim query = From row As DataGridViewRow In DataGridView1.Rows _
Where row.Cells(SelectedColumnIndex).Value = filter _
And row.Visible = False _
Select row Distinct
Datagridview Column Order From Linq Query?
Mar 19, 2010I am using a modal form with a datagridview in order to populate textboxes on a parent form. The datagridview is bound to an anonymous type resulting from a linq query, which varies depending on the textbox control whose keypress event is called. I always want to display a key value in column 0 of the datagridview (along with a variable number of additional columns), and then use that key value once the user selects a row.
However, when setting an anonymous type from a linq query as the datasource for a datagridview control, the columns are indexed alphabetically rather than in the sequence selected in the query. This requires setting the displayindex as a workaround, and then keeping track of which column contains my key value. I read elsewhere that this was something fixed in VS2008 SP1, but I still encounter the behavior.
LINQ Query For Deleting One Column From List(Of)
Jun 28, 2011I have this code:
[Code]...
Return Column Names Of A LINQ Entity?
Feb 2, 2011I am using LINQ to SQL queries to return data in my application. However I find it is now needful for me to return the column Names. Try as I might I have been completely unable to find out how to do this on the internet.
So if my LINQ entity table has the properties (Last_Name, First_name, Middle_Name) I need to return[code]...
Sort Datatable In .net With Linq By Column Index?
Mar 23, 2012I need to sort a datatable. I do it with linq this an example
Dim query = From c In dt.AsEnumerable _
Order By c.Field(Of DateTime?)("LastPurchaseDate"), _
c.Field(Of String)("LastName") Descending
Dim dv As DataView = query.AsDataView
But my problem is that i need to sort the fields not by passing the name of the column but the index of that.
Specify Database Column That Contains A Space In A Linq Statement?
Jun 23, 2010I thought this would have been quite common but can't find anything on this. I'm trying to query columns that have spaces immbedded within them. For the life of me I don't see a way of selecting them when I'm trying to assign them to an alias when creating an anonymous type result. [code]...
View 1 RepliesAsp.net - Create A LINQ Statement Where The Table Name (FROM) And Column Name Is Variable?
May 11, 2012In my programming task I've gone down a dark alley and wished I hadn't, but there is no turning back now.
I'm building up a SQL statement where the table name, column name and id value are retrieved from query string parameters i.e. ("SELECT [{0}] FROM [{1}] WHERE [Id] = {2};", c, t, id)
But it isn't as bad as it looks, I'm protected: Only authenticated users (i.e. signed in users) can execute the Page_Load I'm checking that both the table and the column exists beforehand (using GetSchema etc.)I'm checking that the Id is an integer beforehand All my tables have Id columns The database connection is reasonably secure
[Code]...
Asp.net Mvc - Sorting Datatable With Linq With Correct Datatype Of A Column?
Mar 27, 2012I have this code that use to sort a datatable.
Dim sortingIndex As Integer = orderby
Dim DataTableNew As DataTable = New DataTable
DataTableNew = dt.Clone
Dim query = (From c In dt.AsEnumerable Order By c.Field(Of String)(sortingIndex) Ascending)
query.CopyToDataTable(DataTableNew, LoadOption.OverwriteChanges)
My problem is that with this method I always need (Of String) for it to work, so the date columns are also managed as Strings witch is the problem. Is there a way to use the correct type so the sorting is based on the type of the column?
LINQ To SQL Basic Column Search Doing OR / AND Of A List<string>?
Nov 23, 2011Is there a way to check if a column contains all or any of an items in a list? Example "ABCDEFG" is my column value. "A" "C" "L" is my list stored in a list. I need to find rows that contains at least one item in my list. Then items that contains ALL the items in my list (a basic OR / AND search such as a SE would have)
View 1 RepliesLinq-to-Entities Aggregate A Column That Is Calculated In An External Function?
Feb 21, 2011I want to Sum of the calculated column Red which is calculated in the Function IsRed() that return an integer.When I run the query I get the following error: Method 'Int32 IsRed(Int32)' has no supported translation to SQL.How should I rewrite this to get it to work.
[Code]...
Sql - LINQ Generating Bad Query - Error Unknown Column (MySQL)
Sep 16, 2010I'm developing in MVC2 using VB.NET and MySQL and ran into a problem trying to convert a simple SQL query to LINQ. SQL Query:
[Code]...
Looking at that query its easy to spot whats causing the error. Simply, the most inner query only returns 2 columns, while the query right above it is trying to SELECT 3, thus the Unknown Column Error. So why is this happening? What is wrong with my LINQ query?
C# - Does LINQ To SQL Auto-update The LOCAL/CLIENT Id Column After A SubmitChanges Call?
Jan 18, 2010just want to know if linq to sql auto updated the id column of a class (table row object) after SubmitChanges is called inserting a new row to that table, that would be fantastic, would anyone be able to confirm this?
View 2 Replies[2005] String.Concat Generates A String A Format Not Supported Exception?
Feb 19, 2009The following is ment to generate the path to a text file and stream the data found there into an array.
Dim y1 As String
Dim y2 As String
Dim y3 As String
[code].....
Advantage Of Using String.Concat And String.Copy?
Jan 2, 2009I found this online: The following source code concatenate two strings.
[Code]...
'The Copy method copies contents of a string to another. The Copy method takes a string as input and returns another string with the same contents as the input string. For example, the following code copies str1 to strRes.
[Code]...
LINQ Projections - "Friendly Names" - Use For Column Headers
Mar 25, 2009In LINQ, I'd like to project different names than those from the database tables. "Friendly names" that I can use for column headers. Names that have "%" or possibly a " " (space). The query below won't compile.
Is something like that possible or am I stuck using the dreaded _ underscore for everything?
CODE:
Linq To Sql Null - Check Whether A Column Is Null
Jul 15, 2011How to check whether a column is null i use the following code but I got this error "Input string was not in a correct format."
[Code]....
Add A Checkbox Column At First Column Of Datagridview Including Column Header?
Apr 9, 2010How to add a checkbox column at first column of datagridview including column header?After adding, how to code to "check all" or "uncheck all"?
View 27 Replies
