i want to use linq to fetch data from datatable.I have 2 tables in Cache and i want to join these tables then get value from resultset.I pasted Original Sql query and my linq query here.My linq query returns nothing.Where do i miss?My original sql query returns 1 row,but q1 is nothing
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I am wondering if it is possible to filter data from a datatable.Sample datatable
Quote:
Sno CatID Nos
1 XYZ 25
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I'm trying to do a LINQ Query against a typed datatable that will return me duplicated data.With out going into too much detail, here's the basic setup:
strCode1 - string type
intCode1 - int32 type
intAdjustor - int32
There are more fields but these are the ones that are important.I'm going to do my best to describe this, as it's kind of confusing.In theory intCode1 is a key for strCode1 (hence the names). So each time intCode1 is duplicated, the same strCode1 should appear. Example:
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Ultimately I'd like to get a List(Of T) - where T is my typed data row. In SQL, I would simply use a sub query, to get a distinct list of strCode1 and intCode1, then do a count, grouped by strCode1 where I get more than one row.I'm not sure how to translate that into LINQ, AND get the original types data rows returned in a list.
how to pull/fetch data from SQL DB using Data Reader and loding to XML file.
After that I will have write code to read XML file and download to CSV file and Test files.
How to fetch data from SAP r3 to Oracle with .net?
View 1 RepliesI have a gridview where each columns have two template fields. One is ItemTemplate and another is EditItemTemplate. Now in EditItemTemplate it will show some textboxes where i can perform necessary editing. I can easily fetch data from each cell by using the following code-
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But how can i fetch data when the grid view is not in editing mode that is in ItemTemplate. I have tried the following-
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But its getting the exception object reference is not set to an instance of object. This is probably happening because the above code should be used in a method like RowDataBound when a row is instantiated. But I have to fetch data from some other method.Again for clarification I want to fetch data when the gridview columns are in ItemTemplate Mode.
I want to fetch some data from the database to the DataGridView,so i did this
Dim connString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=Etech.mdb"
Dim myConnection As OleDbConnection = New OleDbConnection
myConnection.ConnectionString = connString
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I am a newbie in VB.net(programming). I need your advice regarding Gridview control.
I have a gridview loaded with two columns-one column(Name)is with some Text,another(Price) is empty.
I have got a TextBox with the data of Name and Price.
Now,I would like to loop through the Textbox,and see if the Data/symbols of the Column(Name) of GridView Control matches with the Data in Textbox.
If the Names of the GridVies First Columns data matches with the names of the Textbox,then the Price data should be fetched in the Second Column(Price) of GridView.[code]...
I have a show button that will fetch data from the database:
Private Sub Show_Btn_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Show_Btn.Click
con = New OleDbConnection("Provider=Microsoft.Jet.Oledb.4.0;Data
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Items collection cannot be modified when the DataSource property is set. How to solve this problem?
I have this form: Attachment 73106 In this form,I want to fetch data from the database(access). Initially when the form loads,the balance field remains disabled. But when i select a data from the dropdownlist of the account number then i want the corresponding data of the balance field from the database is shown in the balance filed of the form and the textbox becomes enabled since it is containing the data. I did this at the form load event:
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I am working on a silverlight project in which i am using the entity data model. I have a consol application in the same solution through which i am creating the database table at runtime. Now when i moves to silverlight page i need to Communicate (load
data from newly created tables).But problem is that without updating the model how i will able to communicate with that table at runtime using entity framework model.
I have created a VB form where I select the "API Type" and click "Generate API" buttoThe dropdown "Environment" should show all users in database. in this casefoo, dead, cafef i select cafe, I want the "changepass" table to be queried and display the password for the user cafe.
View 1 RepliesHow to display data from the database (records) in a vb.net application without a datagrid (i.e in textboxes, and labels) ??
I have used "Add data source and connected my database and also associated the data bindings" but still it doesn't work.
I will attach an image to depict what functionality i'm basically looking for..
[URL]
I want to populate the highlighted controls from a database.
i am creating app , its a question i am stciked at , i am using vb 2008 by using databinding my combobox has the list ready from one column but as selection change the values from all textboxes and labels should change as per the combbox's selection can anyone help
View 10 RepliesI am developing one desktop application using vb.net 2008 and Microsoft SQL Server 2005. fetching the data from database between a given range.
the date field in my table is of type VARCHAR(25) and the date format stored is dd-mm-yyyy. when I using the between clause in the SQL query then it is not giving all the data every time i.e. the date criteria in where clause is not working fine.
while my clients requirement is to keep the date format as dd-mm-yyyy and fetch the data according to the given range.
I search on the forum and found many queries to fetch the data by converting or type casting the date field within sql query but nothing worked.
The table structure that I am using is as follows
USE [Firm_master]
GO
/****** Object: Table [dbo].[tblTransaction] Script Date: 05/17/2011 21:49:11 ******/
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I have a checkbox in my application,when the checkbox is checked then i want to fetch the data from the database and add it to the dropdownlist of the combobox.Again when the checkbox is unchecked then i want to ramove all the data from the dropdownlist of the combobox.
I did this
Private Sub CheckBox1_CheckedChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles CheckBox1.CheckedChanged
If CheckBox1.Checked = True Then
con = New OleDbConnection("Provider=Microsoft.Jet.Oledb.4.0;Data Source=Etech.mdb")
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When the checkbox is checked then the data is added from the database to the dropdownlist of the combobox but when i uncheck it then the data is not removed from the dropdownlist of the combobox. In the above code i think i need to add an else condition to remove the data from the dropdownlist of the combobox and make it empty when the checkbox is unchecked.......but i cant give the proper else condition in the above code.
This is the code that i did to fetch data from the database and filling it to the combobox dropdown list at the form load event:
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I'm trying to convert DataTable to Linq using
DIm result = From r in dt.AsEnumerable()
Select new ( col1 = r.Field<integer>("id"), col2 = r.Field<string>("desc"))
But i get error near 'new (' saying type expected.
I found the following example on [URL] Unfortunately, I need it in VB and it's using some constructs that neither I nor the automated code converters reciognize. Anyone out there know how this should be written in VB.Net? (the problem spot is the "select new {...")
PeopleDataSet ds = new PeopleDataSet();
using (PeopleDataContext context = new PeopleDataContext())
{
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I need help converting datatable to xml using Linq. I could do it with hardcoded column names as you can see in my code .. but i need it without hardcoding it ..Example datatable ..My linq query ..
Dim xmlDoc As New XDocument(
From row In dt.AsEnumerable()
From row In dt.AsEnumerable()[code]......
I'm completely dense here, but I'm trying to get some stats from a DataTable. One of the columns in the datatable is called "colour".I need to find out how many of each instance of "colour" are in the datatable.
I'm trying:
Dim q = From p In PGWorkingDataTable _
Group p By p("colour") Into Group _
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Why does the following code give an error?
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If I change the code to remove the second field, as below, then the code does not give an error.
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discovered the compact mode of this instructions vs usual code. I found sample code for selecting, etc. from a datatable, transforming a column in a list or array - all operations are "Select"s - readonly.I need to make an simple update on a certain rows (using LINQ) from a DISCONNECTED datatable for which now I'm using this
for each dr as datarow in dtable.Rows
dr("MyField") = 77
next
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I have two DataTables:
dt1 - personid, name
dt2 - personid
I want to create a third datatable to include records from dt1 when they are NOT in dt2 using LINQ. In this case, I can bind the third datatable to a dropdownlist.
Am new to the concept Linq.I created a var where i joined 3 tables to get the data and then bind it in a datatable and create a csv file. Now i want to use an additioanl table in the same variable to be bind with the datatable but my problem is i cant use join here since i dnt have any common col or primary col in this additional table.How do i add this extra table?
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I'm writing a small web app in VB.NET and I would like to do paging for my DataTable in the following function :
Public Shared Function Testing(ByVal KeyWord As String, ByVal CurrentPage As Integer, ByVal PageSize As Integer) As DataTable
Dim db As New BibleDataClassesDataContext
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Currently, I am using a loop to find the row I want to update.
Public Sub pubsub_SetUserDGVColumnWidth(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewColumnEventArgs)
' update all user settings for the given column
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I 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.
I wish to output an IEnumerable type (dictionary(of T) would be perfect, otherwise a datatable would be acceptable) that provides an aggregation of the data within the datatable.In SQL I would write the query as such: select groupByColumn, sum(someNumber) from myTable group by groupByColumn
In VB.NET the closest I have got to this (achieved using information here) is: dt is a datatable containing two columns, referred to by index in p below Dim q = From p In dt Group p By p(0) Into Sum(p(1)) Select p(0), SumOfNumber = Sum
However I receive error: "Range variable name can be inferred only from a simple or qualified name with no arguments." on the p(0) element. Therefore my question is as follows:How can I resolve this error? How do I process the result (q) as an IEnumerable type? Life isn't made any easier because I'm using Linq in unfamiliar vb.net. Many examples are in C#, but I haven't really come across anything suitable even in C#.
I write the code below. I want to make short using linq count.
Dim query0 = From obj In dtAginglist _
Where (obj.Field(Of String)("CurrentStatus") = "Open" Or obj.Field(Of String)("CurrentStatus") = "Acknowledge") _
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I try to use code below but it dosen't work with if source is datatable.
Dim orderCounts = From c In customers New With { _
c.CustomerID, Key .OrderCount = c.Orders.Count() }