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 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?
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.
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 I have gone through various books from WROX but none of them show a clear example or the code is obsolete.
I'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.
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)
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]....
I 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
I'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"
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()
[Code]....
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 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
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
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"
I want to create a textbox which contents are validated every time the text in it changes. And an image is displayed beside the textbox if it is correct and another image shows up if its not correct. Pretty much like ajax.
Heres the method which I called from the class.
Public Sub read1() cmd.CommandText = "SELECT * FROM testdb WHERE Name='" & name & "'" Try
[Code]....
Problem is, the method seems to be only called once. And the first image that was displayed stays the same even after inputting a data which does not exist in the database. I'm connecting this program to a mysql database using odbc.
I am trying to use the eID SDK (for using the belgian ID-card) in VB. It's supported but I can't get it to work. I have never worked with sdk's before. I did manage to get it to work in c++ in console but I really need it in visual basic. Also the VB examples that come with the sdk are made in an older version of visual studio and when my version tries to convert them they don't work. I want to use the sdk to see when a card is inserted into the reader and to read out the data. (both i got to work in c++ console).
I have a string which gets data from mssql server, reader collects data (among others also "person) SQLStr = "select * from tablename order by id desc command = New System.Data.SqlClient.SqlCommand(SQLStr, connection) reader = command.ExecuteReader() While reader.Read() ListView1SelectedItem = reader.Item("PERSON") List view contains list of persons (with IDs), including "person" from the reader. What I want is that item from reader.Item("PERSON") is selected/highlighted in the listview.
I have a string which gets data from mssql server, reader collects data (among others also "person). SQLStr = "select * from tablename order by id desc command = New System.Data.SqlClient.SqlCommand(SQLStr, connection) reader = command.ExecuteReader() While reader.Read() ListView1SelectedItem = reader.Item("PERSON")
List view contains list of persons (with IDs), including "person" from the reader. What I want is that item from reader.Item("PERSON") is selected/highlighted in the listview.
I've started from this: ListView1.Items(0).Selected = True ListView1.Select() ListView1.EnsureVisible(0) But it always select first item in list view and not the actual reader.item.
I am working on writing a program that once a magnetic strip card is swiped, the number on the card is validated against a database storing information on the user. What is the best was to get the stream from the USB swipe card reader, build by Magtek, and then just pull the 9 digits I need? I have currently been using an Excel macro that searches the Excel document, but I want to get away from this system and make it more user friendly.
I have two buttons: show button and next button. I want the show button to show the first result and then for every click of the next button, I want to go the the next result. I did this code for the show button: cmd.Parameters.AddWithValue("@sex", TextBox4.Text) dr = cmd.ExecuteScalar If dr.HasRows Then While (dr.Read) TextBox1.Text = dr(0) [Code] .....
Now the number of rows returned is 5. But on clicking the show button I can see only the last row in the textbox's. Then how to see the first row by clicking the show button? And how to see all rows one after another by clicking the next button? I need to use: dr.NextResult() to loop through the fetched data. But I cant place it properly in the next button code. How to do the code for show and next button to get the desired result?
I have a show button.The user will select a data from the dropdown list of the combo and on clicking the show button the corresponding data will be fetched from the database and will be shown in the corresponding fields.So I did this
Private Sub Show_Btn_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Show_Btn.Click Using connection As New OleDbConnection("Provider=Microsoft.Jet.Oledb.4.0;Data Source=BankAccount.mdb") connection.Open() Dim command As New OleDbCommand("Select * from BankAccount", connection) Dim reader As OleDbDataReader = command.ExecuteReader()
