VS 2010 Using LINQ To Filter Data From A Datatable?
Sep 1, 2010I am wondering if it is possible to filter data from a datatable.Sample datatable
Quote:
Sno CatID Nos
1 XYZ 25
[code].....
I am wondering if it is possible to filter data from a datatable.Sample datatable
Quote:
Sno CatID Nos
1 XYZ 25
[code].....
I'm loading a DataGridView from a DataView which collects data from a DataTable. I use the DataView to filter, this is the
Dim dv As New DataView
dv = DataSet4.Tables("TABLA1").DefaultView
dv.RowFilter = "propietario='" + NombrePro + "'"
[code].....
I 'd like to enable the user to apply a custom filter to a System.Data.DataTable.At the moment I have a very simple function like this:
Dim result = dataTable.Select(txtUserInput.Text)
With the filtered results I'd like to do further operations(e.g. Database Update/Delete).Is an sql injection protection needed or is the "Select" function secure?
//Edit:Can the "select" function be abused to manipulate any data in the datatable, execute code, ...? If the only danger is that this function can return to much/to less data there is no problem. But if the data in the dataset gets corrupted it's a real problem.
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
[Code].....
I have a datatable and I apply a filter to the defaultview.rowfilter property of that datatable. If I then loop through the rows collection of the datatable, will I only be able to see those rows that the filter applies to, or will it loop through all the rows?
View 6 RepliesWhen I query a DataTable using LINQ, are the rows returned as references? Either way, is it possible to control this behaviour, so that rows are either returned as references or as new rows?My guess is that all objects are returned as references by default, since that seems to be the normal behaviour in most programming languages.
View 2 RepliesI'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:
[code]...
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.
Example-I have a person class
Public Class Person
Private _fname As String
Public Property Fname() As String
[Code]...
How can I filter data from dataview by Date Like 12-05-2010 to 20-11-2010
View 1 RepliesI have a text file where the second column is numeric fields. All I'm trying to do is only show rows where the field in column 2 is in between txtmin.text and txtmax.text.The strange thing is that the following coding works.[code]
View 1 Repliesi have a datatable with some data, i need to select some of the data, and put that data in a new datatable.
View 1 RepliesI have started a form application using visual studio 2010 express, vb programming. I'm using Access as my database.My goal is to have ComboBox1 display a ProjectID and ComboBox2 display a TestNumber. Once the Test Number is selected I want my textboxes in the form to display fields from the row that the selected Test Number is in.I have 2 tables set up right now "Projects" and "TestData". The "Projects" table has a [ProjectID] field, the remaining fields are just misc. project data. The "TestData" table also has the [ProjectID] field, and then the [TestNumber] field, then the remaining fields are misc. data.
Filling [ProjectID] in textbox1 is easy, in the properties I select DataSource from the Projects table, display [ProjectID] field. Where I'm having troubles is ComboBox2 displaying the TestNumber from the other "TestData" table. If I select that field, it fills the ComboBox with EVERY TestNumber there is. So for Project 1 there is a test 1... over 500 projects, that combobox lists 500 Test 1's, no way to tell what project it belongs to...How do I make ComboBox2 only display Test Numbers that pertain to the Project number selected in ComboBox1?Using this code I can get it to work:
Dim ProjectNo, SQLString As String
Dim dtTableData As New DataTable()
Dim dbDataAdapter As OleDbDataAdapter
[code]....
I also imported system.data.oledb Problem with this code is it will only filter data in ComboBox 2 but when you make your selection from ComboBox2 it won't activate the row so none of my databinding textboxes fill anymore. Before the code/query is ran it fills up the textboxes perfectly after every selection I just have no idea what project that report number belongs to because the whole field is displayed in the dropdown. I can fill the form with ComboBoxes and they display the corresponding row data because I use a "datasource" instead of textbox "databindings" but I don't want to use 20 comboboxes as my entry form...
In the below code, I create a DataTable and filter it. When I use filter1, everything works as expected.When I use filter2, everything works as expected only if the SubsectionAmount variable is less than 10. As soon as I set SubsectionAmount=10, the dr2 array returns Nothing.I can't find what is wrong. Here is the code:
Imports System.Data
Partial Class FilterTest
Inherits System.Web.UI.Page[code]..
I want to filter the data that's being displayed to my datagrid once I click the combobox and select a specific value,the selected value will be the item to filter the data that I needed to be displayed in the datagrid.. I'm using a datatable,a combobox and a datagrid..here's my code
Private Sub cboView_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles cboView.Click
dt = New DataTable
sda = New SqlDataAdapter("SELECT DISTINCT KPIPOSTCODE FROM KKPIGROUP", sqlcon)
sda.Fill(dt)
[code].....
[code]When I call da.fill I am inserting all records from my query. I was then hoping to filter them to display only those where the GroupingID is equal to 0. When I run the above code. I am presented with all the data, the filter did not work. Please can you tell me how to get this working correctly.
View 1 RepliesI need filter for multiple values on one column using the DataTable.Select method.
Dim totalFatal As Integer =
m_DataSet.Tables("tblAccidentNonMotorist").Select(String.Format("[AccidentNumber] = '{0}' AND CONTAINS([InjuryClass], '"01" OR "02" OR "03"'", accidentNumber)).Length
[code].....
I am writing part of a function that tries to search for a username in a list in a rather broad way (last resort). It seems that LIKE does not like trying to match only the first and last characters.
strCriteria = "somename"
drFilter = tblUsers.Select("User LIKE '" & Strings.Left(strCriteria, 1) & "%" & Strings.Right(strCriteria, 1) & "'")
[code]....
How to make the data in the DataTable automatically change when there is the Insert, Update or Delete.my code like this:
VB.NET
Imports System.Data
Imports System.Data.OleDb
[code].....
I have a datatable called dt which includes a column called type.I have a string array called typestringarray with about 15 members
I want to create a new datatable from the rows where type is a member of typestringarray[code]...
Is there anyway to filter a DefaultView with a LIKE-type operator as in MySQL?I want to be able to make it so that in my program, a person can type in a textbox and as they type, the list is refiltered based on what is typed, but I want it to match anything in the string of text, not just starting from the beginning or an exact match.
View 5 RepliesWhat i am doing is to enable a user to specify in a combobox on a form a threshold (integer). On a button click the code steps through a datatable until the cumilative value of a field in the records row are equal or dont exceed the figure specified. It then selects these rows and presents them in a datgridview in another form. This all works just fine.
What i am struggling with is undertaking a sort on another field before it starts the filter part. It appears to revert to the default order. Here is my
If ComboBox1.Text = "Co2 saving in tonnes" Then
Dim table As New DataTable
Dim limit As Integer = ComboBox2.Text ' Your threshold
[Code].....
Public Sub adjectAllNormals()
Dim qry As LinkedList(Of CElement) = From elm In Elements
From id In SelectIDs()
Where elm.ID = id
Console.WriteLine(qry.Count)
End Sub
I'm trying to filter out the time which is greater than 8:00 am and store it in array . Can anyone give me some suggestion?[code]
View 1 RepliesI have a datatable loaded from a database. I bind the datatable to a gridview on page_load. Now I want to filter the gridview by a user selection so I made a checkboxlist and wrote some code as follow at CheckBoxList1_SelectedIndexChanged
[Code]...
With this code above, it can filter if there is only one selection on the checkboxlist. I try to loop the checkboxlist myself but always ended up in errors. Hope someone can help me out to make this work.
Code is:
Private Sub PatientFields()
txtFirstName.Text = pa.Tables(0).Rows(intcurrentindex).Item("Forename").ToString()
txtLastName.Text = pa.Tables(0).Rows(intcurrentindex).Item("Surname").ToString()
[Code]....
Once the search is executed I want to be able to click "refresh" and the original table is then shown in the datagridview. If I try adding after the search sub is completed:
table.DefaultView.RowFilter = Nothing
I have a list(of t) and I got a iqueryable(of a)
I want to filter out any item from the iqueryable(of a) where a.id = t.myotherid
I'm not really sure how to write this query[code]...
I am trying to grasp using Linq to read and filter xml files. I've been googling and trying all day long but still not successful.[code]
1. Firstly I want to select a contact with a certain node value, my code looks like this:[code]
2. The third level nodes have some same descedants child elements. Is it possible to sort the entries by <contactId>? How can I do that? For example I want to have a result like this:[code]
Imagind I have the following in VB:
function doSomething()
From ou In ctxt.Users.Where(Function(p) p.UserName = username)
...
end function
how can I send the filter as parameter (something like below)?
function doSomething(filter as whatTypeHereAndHowToInstantiateInCallingFunction)
From ou In ctxt.Users.Where(filter)
...
end function
Struggling again with doing in VB what I find simple in TSQL (sigh) - hoping that a forum member can point me in the right direction again. I have a datatable with three columns :- A, B & C I am looking to count the number of records in the datatable where columns B & C (both numeric) match specific criteria. eg :-
View 3 RepliesI have following data in the arraylist..
HTML
ID Type Size
1 Car 1 1000
2 Car 2 1100
3 Car 3 1200
[Code]...