I am using MySql 5.0. I using Mupliple datareader in same connection i get error message. Is possible to use multiple Datareader in same connection?
I using Mysql Connection is
MySqlConn.ConnectionString = "SERVER=" & gServerName & ";DATABASE=" & DBname & ";user=" & gUserName & ";password=" & gPassword & ";MultipleActiveResultSets=True"
MySqlConn.Open()
I have a problem with my project. here is the problem:
My code for login is as follows:
dim conn as SqlConnection = New SqlConnection("Data Source.................)
dim cmd as SqlCommand = New SqlCommand("Loguser",conn)
cmd.CammandType = CommandType.StoredProcedure
[CODE]...
Now the error i get is that "there is a datareader associate with this connection that need to be closed"
I'm building application that will heavily use database (about 25k query's in few hours) , what is the best way to go:
A) use datareader and open new connection to the database on every client query.
B) load all the needed tables into dataset once the program loaded and use that dataset for the query's?
I have an SQL statement like:
SELECT FNAME, LNAME, CITY from EMPLOYEE
How do I create a multi-dimensional array from a datareader which should store values like:
John, Doe, LA
Mike, Johnson, PASADENA
Freddy, Kruger, Long Beach
I have multiple documents stored in Attachment data type in Access database. UsingDataReader, I need to read multiple attachments along with their file name and store them on the file system
View 1 Repliesfor example i have this code :
Sub Month()
Dim Conn As New Data.OracleClient.OracleConnection
Conn.Open()
Try
Dim Cmd As New Data.OracleClient.OracleCommand
With Cmd
[Code]...
What will happen to the datareader when the Connection is closed ( Conn.close)
Will the Cursor that is used by the datareader be freed ? or will it stay open ?
If the cursor that is used by the datareader is still open , when will it be automatically closed ? or should i just closed it manually ?
Will it cause the dreaded "ORA-01000: maximum open cursors exceeded" ?
I have a vb.net web app and I am passing a SQL connection and a transaction to a method which writes a single record to the database.
I would like to start and commit a transaction for each record that is written but using the same sql connection until the loop is done.
One method I saw was utilizing a using statement but it didn't work for me.it runs the first time and gives an error on the second that the transaction has already been commited
Using sqlConnection = New SqlConnection(ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString)
[Code]....
I am using datareader to retrieve data. I want to use multiple datareader at a time with same connections. WHen i used it, it gives an error as connection should be closed before using it next time.
View 23 RepliesI'm testing database programming in vb.NET 2008 at the moment and try to find a way to use a database connection in different forms, so e.g. I put the the database-connection-component into one of the forms. I know, I could access it by e.g. form1.databaseconnection.xxx, but is this the best way or can I "put" the connection into something more abstract which all forms know about?
View 2 Repliesis there a function that will allow coders to connect to multiple database? by just changing the connection string and not the variable declaration ...example:connecting to access is something like this
Dim Con As New System.Data.OleDb.OleDbConnection(ConString)
for sql is something like this
Dim Con As New System.Data.SqlClient.SqlConnection(ConString)
is it possible? acctually in vb 6.0 it is possible ...
I have a VB Solution with a dozen forms trying to implement invoice system.My main form (Say Form1) only has a design to create , Edit or Delete Customers.My form 2 will be opened if Create button is clicked. In my form 2, I have textboxes where user can enter Customer details and click on SAVE. My doubt is here....On clicking this SAVE button in Form 2, I want a INSERT command to happen on the MSAccess's Database table called Customer (which I have already created... this table does not have any records as of now). In my form 1, I added a MSAccess Database with a Connection String. In my Form1's code I have code like this[code]...I got this piece of code from this link [1]: vb.net - sharing mdb access connection among multiple forms/Now, I do not know what more code does this require to INSERT records from my text box into the Customer table's fields.
View 1 RepliesI'm starting to put in a database into my application, however I'm drawing a blank on how to share a database connection among the dozen or so different forms in my MDI application. I'm assuming this has to do with interfaces or something but I can't find any relevant examples anywhere. Can someone help me out? Ideally what I'd like is when the app is loaded up there is a call to a function in the forms loading area which establishes a single connection to the mdb, that I can then call via any form so I don't always have to open/close connections everytime I need to update the db?
Here's a basic example of the mdb database access code I've got working:
Dim dt As DataTable = New DataTable()
Dim OleDbTran As OleDbTransaction = Nothing
Using connJET As OleDbConnection = New OleDbConnection("connection string here...")
[code]....
Am developing a server - client application using the system.net class , that will have more than 5000 simultenous client connection.what is the best way to manage multiple client connection like this?
View 3 RepliesI am creating an VB 2008 application which uses 2 connections strings in according in which computer is running (my test machine, and the production server). How should i manage the connection string in order not to change manually the connections string which are many inside the code??
I have read that you can read them from an external line, or if you put both connection strings in an external file, according in which machine the program is running can actually the correct string?
I want to make a simultaneous connection to multiple servers with threads, only to create a single connection.
Imports System.IO
Imports System.Net.Sockets
Imports System.Text
[Code].....
I have an application that I made in VB.NET. I put it in the server on my office and every other user access it via network connection. I only mapped the drive onto their computer and then I cope the shortcut to the application. can I close all the application that is running with a single code? I sometime need to close all the application first before I can do anything with the application (for example, modifying the report etc.). My current method is still the manual one, which is calling everyone to close their application or running all over the place closing the application myself.
View 1 RepliesI have the below mentioned code in a seperate class file for establishing connection and carry out DB transactions. I have an issue where multiple connections being opened which sometime exceed the connection pool. When I stepped through the code I found that there are codes which call ConnectDB() in a loop without calling DisconnectDB(). But I expected that the condition OraConn.State = ConnectionState.Closed should handle the situation. Somehow the condition is always satisfied hence openning another set of connection. Can you suggest where am I going wrong and also what best practice can be adopted here?
[Code]...
The connection is again opened in function updData(). While I understand that it has to be closed correctly but keeping tab on every developer is not possible. Hence I want to control it directly from the connection class by using the same connection but the condition If OraConn.State = ConnectionState.
UPDATE I have put the code in UpdateDB under a Using block and removed call to ConnectDB and DisconnectDB from function like InsertData(...). It seems that the issue has been resolved. But I would like to know in case of exception will the connection remain open? and also OraConn is a public variable defined outside Using block so will it be disposed of by the GC?
[Code]...
i am working on a search feature for a program i am working on and i found a tutorial online that provides some insight but the actual code, after being modified to fit my aplication, does not work. i get two different errors as of right now, one that tells me "the value of type 'System.data.sqlclient.sqldatareader' cannot be converted to '1-dimensional array of system.data.sqlclient.sqldatareader" and the other that says"argument not specified for parameter 'array' of 'Public shared function... anyway i am kinda new to this and here is what i have so far. any advice?
Private Sub SearchOKButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SearchOKButton.Click
[Code]...
I have the following code which does what it's supposed to do:
objSQLCommand = New SqlCommand("select * from table1", objSQLConnection)
objSQLCommand.Connection.Open()
objSQLDataReader = objSQLCommand.ExecuteReader()
While objSQLDataReader.Read()
[Code]....
But I need to loop through the objSQLDataReader 1 more time. How would I do that?
I got the error message There is an open data reader associated with this command which needs to be closed first by using the following code:
myCommand = New SqlCommand("SELECT BookCode FROM tblBook",myConnection)
myReader = myCommand.ExceuteReader
While myReader.Read
[Code]...
How do I assign a My.Settings.Item connection string to cmd.Connection connection string value?
Dim cmd As New SqlCommand()
cmd.Connection = My.Settings.Item("csStaffHoursWorked")
cmd.CommandType = CommandType.StoredProcedure
cmd.CommandText = "spSaveDeltekImport"
I am copying sample.csv file's content into the new.csv file. But I need to add additional column in new.csv file which holds the default value as "Yes" for each row that exists in old file. Here is the code I have written.
Dim ioFile As New System.IO.StreamReader("C:sample.csv")
Dim ioLine As String
Dim ioLines As String[code].....
The first four columns ID,Name,Number,Amount are present in sample.csv.I am adding additional column Copied which should be "Yes" for each row.
If my Select statement finds data that matches the criteria, how do I get myReader (DataReader) to read each record when there are more then one record found?
Dim myReader As MySql.Data.MySqlClient.MySqlDataReader
myReader = myCommand.ExecuteReader()
If myReader.Read() Then
[code]....
I am trying to tag of some words.There are 5 tag word in my database. but only the first record is coming.i want to
my codes
Public Function tags(ByVal ID As Integer) As String
[code].....
my html code in gridview <%#tags(Container.DataItem("ID"))%>
Hey Friend i am using a form with a *combobox*in which the items i have taken from the
sqldatabase named as balance and that sqldatabase have two columns one is customername and the
another is obbalance now .
In the form i had binded all the customer names from the table and now i have a textbox i want to do is
when the user selects the combobox.selected item any one customer name i need to display the obbalance of the selected customer in tat textbox
[Code]...
two DataReader in one TreeView ?
I am working on a project which requires me to connect to a MySQL database. From there I query the database and need to do work on the returned values.
I can query the database just fine. However, now I need to do work on the results. The two columns returned are user_name and user_password. The rows are the user accounts. I would like to take my query results and put each column into its own arrary().
[code..]
Instead of writing the results to the console, I would like to write each column to an individual array. Is there an easier way to accomplish this task? Or, what is the code I must place within the loop to do this.
i want to fill a Datatable with a Datareader row by row but get an exception because the reader's columns have a different order than the Datatable's columns.
Why and how does a Datatable loads itself with a Datareader correctly, even so it has a column collection with different order?
I need to calculate values for every row so i dont want to load the Datatable completely but row for row. It has 25 columns so i dont want to set it all manually.
There must be a chance to load/fill/add a new row from a datareader without having the same column order(reader.GetSchemaTable?).
Following is what i have but what doesnt work:
Using reader As System.Data.SqlClient.SqlDataReader = command.ExecuteReader
'next line works(configInfo.DataSource is a Datatable)but is inappropriate
configInfo.DataSource.Load(reader)
[Code].....
I have this sub as part of my login / logout system. When this sub is called to login users it works perfectly, but on logout it throws an error that doesn't make any sense to me.
[Code]...
This sets a nonsense email address so that when validate_session searches for a valid email/session combo in the db it trips the destruction of the sensitive session data.
The question boils down to this: Why is the error being thrown when the logout sub calls validate_session?
Is there an easy way to reset or clear a DataReader so it can be read through more than one time? I found a Close method but not an open method.
View 1 Replies