I am trying to create a datatable in VB.NET, but when I output a row from this table it shows: "System.Data.DataRow".I have compared my code to several websites and it seems correct. However if I instead Response.Write these values they display correctly.
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I have a datatable with three columns
Id name value value1
I want to create a string from this datatable so that each row in datatable will create two rows name will become one row value 1 will become another row
If name and value1 are similar then include value 1 only otherwise include both name and value1 (this is done)
If name of one row is similar to name in any other row, then add following text infront of both duplicate rows in string
Id is similar to Id
This is what I have written so far:
Public Function GetGazetteer(dataTable As DataTable) As String
Dim processedData = New List(Of String)
Dim rowData = String.Empty[code]....
So I'm sure this sample code exists somewhere, but at this point I just need some guidance. What I am trying to do is import all of the data from a CSV I have (it's about 100 columns of data that are numbers, not strings, and have headers) and create a DataTable so that I can plot to a 3rd party chart control called Zedgraph. The problem is that when I plot columns from the DataTable that is created by the following code, it simply plots a diagonal line of the points count (in other words, if I create a curve from a column containing 400 data points, it plots a line from 0,0 to 400,400, instead of plotting the actual data). What I think I have finally figured out is that I'm importing the data as String, rather than Double or whatever other number type I could use. The problem is that I cannot seem to get any OLEDB connection to actually fill my dataset, so I have had to stick with this code for now. FYI, I am using Visual Basic Express 2010 and the file is a CSV created from Excel 2007. [code]...
View 2 RepliesI want to make 2 planning forms, one for persons and one for materials. The most ideal situation is when it can be in 1 form and switched by using an option field at the top.
- The information is coming from a SQL 2008 database.
- Vertical the persons or materials must be shown(dependent of the option field).
- Horizontal every day of the year must be shown, so the number of columns will be 365.
- At the crossing the number of hours must be shown.
- The form must be build as fast as possible.
I tried to create a datatable dynamicly and use a Datagridview. The advantage is the information, which must be shown, can easily be changed. The disadvantage is it is slow.What is the best method to do this in VB2008?
I want to loop through my datatable column called SDESCR and created a string that looks like this.
Dim labels As String() = {"North", "South", "East", "West", "Up", "Down"}
this is what i am trying and it is not working
Dim labels As String()
For Each row As DataRow In tablegraph.Rows
labels = labels " ' " + row.Item("SDESCR") + " ',"
Next row
Scenario is this; I've a sqldatareader query that seems to be returning nothing when I try to convert the sqldatareader to a datatable using datatable.load.So I debug into it, I grab the verbose SQL query before it goes into the sqldatareader, just to make sure it's formatted correctly. I copy and paste this into SQL server to run it and see if it returns anything. It does, one row.I go back to visual studio and let the program continue, I create a datatable and try to load the sqldatareader but it just returns an empty reader. I'm baffled as to what's going on. [code] Ok I've done a loop to count the rows of the datareader before using the datatable.load method. In my test query I'm getting 4 rows (the correct amount) in the datareader, as soon as I use the datatable.load method it says the datatable is empty, what's going on?! So it seems a datareader is a one-way thing, iterate through it to get the row count and it's essentially empty as far as any other bit of code is concerned. Didn't realise it was forward only and wouldn't 'reset' once read through.
View 1 RepliesI am trying to create a datatable to be shown in a datagridview.. i have created a DataGridViewComboBoxColumn that has a data source and now i wanted to create a DataGridViewTextBoxColumn but i dont know how to make it take its data from a column in a table.. i did it with the comboboxcolumn but i coudnt do it with the textboxcolumn..
View 2 RepliesI want to create a datatable using he contents of a DataGridView.
View 9 RepliesHow to create a dataview from a datatable?
What is the basic use of the created dataview?
I have two datatables, which come from different sources. One is Sales, the other is Products. What I'd like to do is create a filtered version of Sales, in that in that it contains Sales which have a matching ProductID in Products.
View 11 RepliesCODE:
I am working on a winform project. like to display result of datatable in a dynamically created chexboxes.see sample picture.
How can I create datatable in windows application in C#.net. I want to store a temporary data into the datagridview from textbox to grid. I know it work in asp.net. Is it possible in windows application C#.
View 2 RepliesHow to create datatable with multiple records.
View 6 RepliesI have a question related with VB.Net Code. I see that the DataTable we can use: DataTable(0)'This return a DataRow with the selected index In the intellisense I see that this functionality can achieve with a extension... but, If I create a extension, always I need refer the Extension before to use it
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I've got a calendar app where we're loading up a DataTable from one method, then merging the results with another method - both methods return the same type of data and the same columns. One of the columns in the results is "start_time", which has a date and time. What I want to do is sort the entire, merged, DataTable by the time in the "start_time" column, disregarding the date completely. I've gotten this far, but can't see how to get it done:
Public Function GetDates(ByVal dStart As DateTime, ByVal dEnd As DateTime, ByVal nPageId As Integer) As DataTable
Dim dt As DataTable
[Code]....
I think I need to create a new column and grab the time from the start_time column and then re-sort the table
Probably a very dumb question but I have a program whereby I create and populate an in memory datatable, which I then add to a data-set. I then run a couple of updates on the dataset and need to know how to then send these updates down into the in memory datatable :Here is a mock up of the code structure following the creation and population of the table :
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I have a Datatable consisting of columns with Latitude and longitude I want to be able to pass through each of those values in each row into an array that can then be passed through a function which gets the distance between each row and a static. In short I am trying to get distance between one location and various others that reside in a datatable that will vary in size. Right now with this existing code I am getting 6 different locations into an array:
HTML
Public Function GetCoords() As Coord()
Dim myCoords() As Coord
myCoords(0).Lat1 = CDbl(list1_Lat.Text)
myCoords(0).Lon1 = CDbl(List1_Lon.Text)
[Code] .....
If I am on the right track I think I need to create a new array that will accept Lat and Lon from each row in my Datatable? My end goal is to be able to find properties within a certain distance of a property. In other words "return all properties that are within .25 miles of 12 Maple Street". I thought if I had Lat and Lon of a certain property there would be a formula that would give me the max and min Lat and Lon to be within a .25 mile radius. I have searched for how to get a radius, but didnt come up with anything I could comprehend. So instead I thought I would just get each properties (row) return the distance in a new column then loop through the table to return properties within the desired distance .25 miles etc...
Our shop primarily use "ADO objects" (I'm referring to DataSet, DataTable, and DataRow) for marshaling around data and manipulating it on forms and in grids. We are experimenting with creating shop-flavored counterparts to the native ADO objects so that we can impose our in-house standards on top of them. Implementing this is straightforward with one exception: I want our objects to be bindable to controls.
I'm aware of IList, IBindingList, BindingSource, etc. and have looked at and experimented with these, but I am falling short when it comes to making a class with no hard property names bindable. The native ADO objects are not strongly typed by default. You have column values that you access via the Item property (e.g. row("Age") or row.Item("Age")). The binding examples I've found online deal with strong-typed objects (e.g. row.Age). Essentially, we want to create custom ADO objects (not inherited from the native ones) that still retain their ability to bind to controls. In a grid I would expect to see columns Name, Age and Occupation from a row where these properties are exposed via row("Name"), row("Age") and row("Occupation"). This must be doable as this is exactly what the native DataTable and DataRow provide.
I have a table with 2 rows named timeStamp and value. I know I can iterate through the rows and create points and add them to a list (new point(timeStamp,value), but is there a way to do it without iteration?
View 11 RepliesMy code is crap, so I don't really think it will be useful because I've been going about it differently than I really want to:[code].....
I really don't wanna be loading a file in, I just wanna use XMLDocument() to create a file from my DataTable.But, my file ain't coming out right and I'm sorta just lost as to how this is all supposed to fit together.
I want to select column 'F1' from an excel spreadsheet and dump the data into my datatable 'oleDT'. How do I map the column F1 to the column i've added called 'colTest' ? When i call Fill, the dataTable has 2 columns, which are 'colTest' full of nulls and a created column called F1.[code]...
View 1 Repliesim trying to select some rows based on a criteria, i was wondering is it faster if i create a dataview (based on the criteria) and then loop through the view? or should i loop through the entire datatable and check the criteria manually.
View 5 RepliesI have to generate an XML file from several database tables. I could use the WriteXml method of the DataSet to do it, but the database tables are really huge and I can't add all those tables in the DataSet at the same time or it may cause a problem because of the big amount of memory used. Then I decided to use the DataTable's WriteXml method and save table after table, but the the generated file only stores the information of the last DataTable.WriteXml's call. How can I preserve the previous XML data when adding all that information?
View 4 RepliesNew to reports here. Using VB.NET, my application makes use of datatables it creates from a postgresql database.These datatables are defined at runtime rather than design-time, and I would like some way of generating reports from these datatables at runtime as well.
Should I be trying to create the report template at design-time, and then "binding" a datatable to it at runtime?
I am trying to display value of the field ("UserID") for every row exists in datatable to checkboxlist(make the checkboxlist item selected).
I used for loop, but only the field value from last row of RoleUsers table is selected in the checkboxlist.
Here is my code
Private Sub DisplayRoleUser()
Dim conn As SqlConnection
Dim cmd As SqlCommand
[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 RepliesI am working on a project that takes an xml schema and xml data files and places them into a DataTable, the 2 files are generated from a working table that i have written to disk. I wish to load these 2 files into a DataTable. Here is What i have
vb.net
Friend Function CreateTable(ByVal tableName As String) As Boolean
Dim table As New DataTable(tableName)
table.ReadXmlSchema(tableName & ".xsd")
[code]....
this however produces the following error on line 3
Quote:
System.ArgumentException was unhandled Message=DataTable 'get_item_list' does not match to any DataTable in source.
get_item_list is the parameter passed into this function (tableName)
I have an application where there is a sub that creates a new datatable object. This line of code will randomly generate the following error;
View 4 RepliesI have a datagridview bound to a datatable setting its datasource property to the datatable. I would like to have a child form that contains a list of columns associated with the datatable that contains a checkbox that will allow the user to hide and show the columns ( I do not know the best control to use here) (I assume this is the easy part as All i need to do is loop through each of the datatable's columns to get the column name)
now I would like save these visible columns on some event like form_closing so that the next time the user opens the form up it will remember the settings
I came across a problem with using a BindingSource as my DataGridViews.DataSource. Whenever I applied a filter to a column in the BindingSource and the user makes changes that don't match the column filter the DataGridViewRows would automatically disappear. A similar thing would happen when applying a Sort to a column. If the user made any changes the DridGirdViewRows would automatically sort causing rows to be moved around. This was not ideal for my application and there isn't anyway to stop this from happening with the BindingSource.
To correct this issue I have to use subsets of data. I use a DataView to apply the filter and sort to the main DataTable, which creates the subset DataTable.The problem is when I use the DataView.ToTable method I loose the Primary Key and RowError information. So I have to reapply this information everytime the user filters or sorts the DataGridView.Is there a better way to get a subset DataTable?[code]...