I have a table in my database and I want to return the rows in a data reader and retrieve them in variables. I can do that well but I can only return the last record. The reader doesn't process all the rows.
Try
Dim myconecction As String
myconecction = My.Settings.DataSource
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i have create a procedure to return data reader value, but it not return and returning null reference?
'Public Shared Sub GetData(ByVal Tablename As String, ByVal queryfield As String, ByVal Id As String, ByVal lblmsg As Label)
' Try
' Dim Cons As OleDb.OleDbConnection = DBHelper.GetConnection
' Dim Com As OleDb.OleDbCommand = New OleDb.OleDbCommand("Select * FROM [" & Tablename & "] WHERE [" & queryfield & "]=" & Val(Id), Cons)
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I have this application which has one class. I need to return a recordset of data to the calling form. If i use Properties to return, it can only return only a single value at a time. Right now i'm returning a datareader object with one of the properties.Can anyone suggest a better way to return multiple rows of data to the calling method via Class Property?
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What would be wrong in the above code. ExecuteReader is throwing excepion. Invalid cast from string to GUID. But My Sqlparamter was already uniqueidentifier nothing cast.[code]...
I have an error that is during the query to a database ExecuteReader 'phase' of my program, i am assigning an .OleDbDataReader to a variable RetVal and then, i am giving this RetVal = Query.ExecuteReader, and then in the while the query is being read loop(While RetVal.Read) i am getting an error in runtime that is "Invalid attempt to call Read when reader is closed." I know this means i have to open the reader, but i don't know how to do this, as i have been using this process for a few weeks and haven't had this error pop up. (and i have managed to use the while loop)If you're not living on the edge, you're taking up too much room
View 7 RepliesThere is something wrong with my filter expression it isnt working. I am simply trying to return the rows that have a CompanyID of mCurrentID. objts is a datatable
Dim mCurrentID As String = lookupInTrenCustomer.EditValue
'populate grid here
Dim mFilter As String = "CompanyID=" & mCurrentID
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I have the following code that loads an XML file into a datatable (I went this route because I do not know how to query XML directly). I want to use the Select method to return a row where "age = 72". However, I can't seem to get this to work. Also, if there is a better way to search through a datatable for specifc values that would not require iterating through the whole table to get the results
Imports System.Xml
Module Module1
Sub Main()
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I'm having the datatable with three columns, i need to return the rows in which the third column having the null values.
ie., I need to do like this below mentioned coding,
Dim rows As DataRow() = ds.Tables("Tablename").Select("col3 is null")
Is it possible? if no, anyone tell me the way to get the results.
My datagridview.rows.rowcount always returns 1 no matter how many rows i have in myatagridview?The datagridview is populated by a loop in another function
View 4 Replieswhen populating a data grid i keep getting a redundant row in the bottom. is there a way to lock grid rows to the number of rows in the data table?
View 1 Replieshow 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.
can data reader be used as a data source for a grid control?
View 5 Replies1 within each section of a SplitContainer. The left hand side will be for inputing text that is copied/pasted from a word, excell, or text file.The right hand side would be for my output. What I would like it to do is return just the rows from the left hand side that contain a match to any one of the predifined strings. This will be used to search large lists of company names and circuit IDs and return the rows with matching namesSo far I have the form created, the Splitcontainer in place along with the richtextbox on each side and a submit button at the bottom.
View 12 RepliesI've got two tables:
tClient:
ClientID Name=============1 John2 Sally3 Joe4 Nick
tInvoice:
InvoiceID ClientID DateAdded==========================1 1 2010/09/012 1 2010/09/023 3 2010/09/01
I'm trying to write sproc where I need the following info:
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I have a data reader "dr " that returns a row fo data, Assume dr returns values of 6 columns I need to create an instance of DatarRow using "dr", so that later I can create a collection of datarow objects that I will be adding to a table. However, how do I create a DataRow using dr object?
View 1 RepliesCurrently i am using this code
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How do I really use data reader in vb.net. I'm using odbc to connect mysql and vb.net. Function I declared on a module:
Public Function form2search(ByVal drugname As String) As OdbcDataReader
cmd.CommandText = "SELECT * FROM drug WHERE Drug_name LIKE'%" & drugname & "' "
Return cmd.ExecuteReader
End Function
[Code] .....
I see a result, but it only loads the first item on the database. I've put this code in the text_changed event. What's the proper way of doing this? And what's wrong with the 2nd code, why is it only loading the first data. As you can see the con is the module where I declared the function. Then I created an object of it in the form.
I want to launch a application called Foxit Reader pdf Reader .I know System.Diagnostics.Process.Start(path) can do it but . Requirements are Foxit Reader should be installed on machine.Now if it is installed how to serarch for the path of its Executable to provide the parameter as I can not hardcode the path for different machines.
View 3 RepliesI am using SQl data reader to get value from SQL database.Language VB.NET.After getting data into reader, i run a while loop
While reader.Read
If reader.HasRows() Then
/* Proessing of data *[code]....
Are there any examples on how to implement a datareader? I have try copying the code from MSDN but;--"Dim reader as SQLDataReader = command. ExecuteReader()"Where it is placed? As a declariton at the beggining of a form? or as as VB resource?and then how those it bind a to a dataGridView? How can I loop through each rows once is bind to use the contents of the column/row?I can perform the above function easly inside of MS Access using VBA. I have gone through various books from WROX but none of them show a clear example or the code is obsolete.
View 5 RepliesI'm switching over from PHP to vb.net. And some of the concepts are a bit different. Mainly I struggle with concepts and keywords, so it hard to look stuff up. Currently I'm creating a dashboard and needs to run a lot of different sql queries. But I see where I should be able to minimize my code. But things that I have tired don't work. Example below of two chunks of code that I should be able to put in some type of loop and increment a value for my sqlstring and textbox output.
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I'm using VB 2008 to received data from serial port (RFID Reader). below is the coding that i used. the problem's, the RFID Tag number does not display on the textboxt. [code]....
View 11 RepliesHow can i check if some value exists in the data reader
View 7 RepliesI have the first form and create 5 checkboxes which are connected to my db. Whichever checkbox is checked and the value will be inserted into the db (value: 1; data type: tinyint).And now, the second form will pull out the data base on the which checkbox is checked when the button is clicked. But for somehow i got stucked at the following code.
The first form:
Dim nValue As Boolean
If chkbox5.Checked = True Then
nValue = 1
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I have a column ("Notes") in a sqlexpress database as nvarchar(1000). It will basically hold notes. It is pulled froma richtextbox control.[code]...
View 2 RepliesI'm having a bit of trouble developing my login page! Currently i have 2 text boxes which a user can input a username and password. My form should then check whether this data relates to the data in the database and either grant or deny access.The error i'm receiving occurs at the line "If theDataReader.HasRows Then"It says 'The data reader has been used before it is assigned a value"
Here is my code:
Imports
System.Data.SqlClient
Partial
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How to populate a combo box using SQL Data Reader in DAL, BAL and UI atmosphere. Please find below my code snippets and correct me if I'm wrong anywhere in this code.
'DAL Code
Public Function PopulateComboBox() As SqlDataReader
_cnCon = New SqlConnection(_conString)
_cnCon.Open()
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What should be the UI code? Is the code specified in DAL and BAL is correct? I knoiw how to fill the combo box with values from SQL Data Reader. But I dont know how this can be done in 3 Tier application.
I'm using the following function to generate a list of users connected to a selected database. How would I change this to a single line for multiple identical results?For example: "sa (3) - MYCOMPUTER" rather than listing "sa - MYCOMPUTER" three times?
Function ConnectedUsers(ByVal SelectedDatabase As String, ByVal SelectedInstance As String)
Dim myCommand As SqlCommand
Dim dr As SqlDataReader
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I've set up a stream reader to get data from a serial file, functionality for that is already set up.
My problem is that the program seems to be missing out every other line of code in the file, which kinda defeats the point of a serial file. [code]...
I am having an issue with both Adobe Reader and FoxIt Reader when trying to print a PDF document. Both issues are different but a solution to either one will allow me to fix my issue.The issue I am having with Adobe Reader when trying to print using the following code is that it will not print it to the network printer I specify but just the default printer.
Dim AdobeReader As New Process
AdobeReader.StartInfo.CreateNoWindow = False
AdobeReader.StartInfo.Verb = "print"
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