I have one multi-row INSERT statement (300 or so sets of values) that I would like to commit to the MySQL database in an all-or-nothing fashion. insert into table VALUES
(1, 2, 3),
(4, 5, 6),
(7, 8, 9);
In some cases, a set of values in the command will not meet the criteria of the table (duplicate key, for example). When that happens I do not want any of the previous sets added to the database. I've implemented this with the following code, however, my rollback command doesn't appear to be making a difference. I've used this documentation: http://dev.mysql.com/doc/refman/5.0/es/connector-net-examples-mysqltransaction.html
Dim transaction As MySqlTransaction = sqlConnection.BeginTransaction()
sqlCommand = New MySqlCommand(insertStr, sqlConnection, transaction)
Try
[code]....
I get the DUPLICATE KEY exception thrown, no Rollback Exception thrown, and every set of values up to duplicate key committed to the database.
I'm using an Entity Framework context, and sometimes would like to create a transaction so that the client can do multiple changes and then commit/rollback them all together.However, if many changes were made, and SaveChanges() was called multiple times, after which a rollback is called, entities that were commited already, will remain the way they were commited, and would not roll back.Here's how my transaction-relative functions look like:
Public Sub BeginTransaction() Dim context = HttpContext.Current.GetObjectContext() If Not context.Connection.State = ConnectionState.Open Then context.Connection.Open() End If
[Code]...
Not only does the test fail, but it also leave the ObjectContext in an unstable mode, because it still has invalid changes in it.
What i have going on, is i have a MySQL connector as a resource on my application, and im basically trying to connect to my MySQL server, to either a) register a new account, or b) check that the account exists and they are premium, and login, Now what i have run into problems with is: My MySQL Database Name has a _ in it which VB is not allowing for some strange reason.
The code i am using is below
Imports MySql.Data.MySqlClient
Public Class Form1
Function UpdateRecord(ByVal query As String) As Integer
[CODE]...
How i can allow the _ into the application, because the only databases that don't have a _ in the user or dbname are a) Paid ones which i DO NOT have the money for or self hosted ones, i cannot leave my computer on 24/7
i Built A MySQL Login System Using MySQL Connector But If Other People Want To Use The Program Thay Get An Error, I Think This Is Due To Thay Do Not Have The Connector So What Should I Do, Btw Dont Say 'Tell Them To Connector'!
Im building an app to manage PSP contents, and it should connect to my MySQL server on my domain to refresh game info and ratings and so on, but I cant make it connect with MySQL Connector 6.1.
I can have mysql database. but i have not mysql. how to connect this database vb.net 2005. but i have mysql-connector-net . I want to mysql-connector-net use to connect this database. database path(C:Documents and SettingsAdminMy DocumentsVB.NETStock delnaSTC.sql)
if one installer class in my project and in custom action doing some procedure to validate the serial key using user interface editor during setup creation. while installing the set up if the condition is not true the setup in rolling back it is installing.
I'm having a problem connecting my DB to a crystal report. I have tried to databinding my DB in MySql but it seems that it cannot produce the data needed but the fields are there..
here is what i have done to my crystal report. i think i have missed something
I am developing an application with VB using the MySQL Connector Net [URL]. Now each time I go to load data in to a datagridview or in to text boxes on a form, I have to provide something along the lines of:
Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click 'Create connection to MySQL Database Dim conn As New MySqlConnection Dim myCommand As New MySqlCommand conn.ConnectionString = MySQLGlobal [Code] .....
I think it would be better to leave the connection open to the MySQL database while the application is in use. That way I can just continue to execute queries of inserting and updating, without having the delay of the application having to reconnect. Is there a way where I can create some sort of background task in the application that monitors every few seconds that the connection is still active, and if not it tries to reconnect until its reconnected? I am trying to have it so that then I can code it to just do queries, and when the connection breaks - it disables the form until it is reconnected.
I've got a vb app that writes data to a remote mysql database.
When I run the app on a client that does not have the mysql connector it crashes (obviously)
How do I programatically check if the connector is installed on the client and throw up a nice error advising to install it - instead of the unhandled exception error - could not load mysql.data etc error?
I am am currently developing an application using Visual Basic 2005 and I am also using the .NET MySQL Connector. I have noticed that when the MySQL Connector executes a query the application freezes for a bit so I was wondering if it is possible to create another application with textboxes, labels, etc, that will be hidden and will execute these queries, but the main application will be able to read and modify data on the hidden application so that it won't freeze.
So, what I'm trying to do is to connect to a remote database using the MySQL connector. Dim c As New MySqlConnection c.ConnectionString = "Server=" & URL & ";Database=" & "" & ";Uid=root" & ";password =" & "" c.Open()I know the connection string is correct. I can access the phpMyAdmin through a web-browser just fine. For some reason however trying to open the connection throws an exception 'Unable to connect to any of the specified MySQL hosts'. I tried disabling the VS debugging process, as I thought maybe it's blocking my MySQL access for some reason, but no.
I have a series of DML and DDL(Drop View only) statements that I need to execute under single transaction from VB.net app. I m using commandObj, and kept above all I kept beginTransaction statement. Everything is working fine expect when error is returned by Drop statement. If Drop statement returns error then whole transaction is rolledback. I do not want tthis. I want to continue even if Drop fails keeping the other DML statements that were executed before Drop.
I get this error at the Commit of a transaction in a desktop application:
This OleDbTransaction has completed; it is no longer usable.
Other posts I have seen with similar error suggests this can occur if it takes a long time, or contains large amounts of data. This is not the case here.Logging tells me it takes 140 ms from Begin to Commit and about 10 commands executed inside the transaction.It is using an Oracle database.This class is a simplified version of my database class:
Class MyDatabase Private mConnection AS OleDbConnection Private mTransaction AS OleDbTransaction
[code]....
Is it not allowed to run a select inside a transaction like this? Or can it be done by running the transaction in a specific isolation level (I see that the BeginTransaction method has an optional parameter for doing this) ? ..Or some other sollution..? In my case, it was not a problem to move the select to run before the transaction started, but what if you need to run selects that must run inside the transaction?
I've seen plenty of examples of transactions in the actual store procedure's SQL. But I'm wanting to do the transaction and keep track of it in code. I tried this but it says that my insertcommand's transaction object is null. How can I fix this?
vb Dim conn As SqlConnection = DBConnections.SQLServerConnection conn.Open() Dim params(1) As SqlParameter
Error : Execute requires the command to have a transaction object when the connection assigned to the command is in a pending local transaction. The transaction property of the command has not been initialized..
This one causes the error: Dim oOperation As COperationOutputTypeBS oOperation = COperationOutputTypeBS.GetOperationOutputType(txtOperationCode.Text)
how to connect a visual basic front end with a MySQL back end. I am not proficient in VB or MySQL and was not able to find anything on google as a result.
I'm trying to create a game that involves rolling a dice. When I load the program and click the btnRoll button, the dice works fine and stops after a random number (between 10 and 20) of face changes. It then records the score in the a new line in a ListBox. Only problem is, when I press the roll button again, the face only changes once before recording the result.
I have tried creating a separate program that simply rolls the dice without recording the result, and it works fine. So I used roughly the same code in my game, but it still won't work. I have tried looking online for help for a few days now, so I figured this would be a good time to ask here.[code]...
I would like to have some sort of percentage on the amount of times each button has been pressede.gButton 1 is pressed 5 times, button 2 is pressed 3 times, button 3 is pressed 2 times.I would like this to create a percentage output onto the same form that is updated everytime a button is pressed on the form.
I'm trying to calculate the rolling average in a crystal report. I have got 4 weeks in a month, and I have calculated the average for each week so long. Now I want to calculate a rolling average. eg:
For week1: rolling average = (week1Average)/1 For week2: rolling average = (week1Average + week2Average)/2 For week3: rolling average = (week1Average + week2Average + week3Average)/3 etc.
The problem with the code below is that, it is not looping through,therefore the rolling average for each week is the same as its average value wich is not correct.
Dim i, weekNum as number Dim tot as double weekNum =Distinctcount({ItemRating.WeekNo})
I have a certain problem with 2 number generators that I have. My problem is that I want them to act individually. To where they seperatly come up with a random number. Mine is from 1-6 for 2 random number to simulate the rolling of two 6 sided dice. The problem that I have is that when I run the program they always generate the same number no matter what that number is. When I step through it step by step while the program is running in the debug screen they come up with a different number. This is in visual basic 2010 express edition.
Private Sub Button1_Click(ByVal sender As System.Object, [Code] .....
I'm doing some maintenance on some software originally built by my predecessor at the company (who has since moved on to greener pastures). I'm currently rolling out a new version of the software. At this company, the installation procedure is basically to just shove the /bin/Release directory out into our automated program updater's magic directory, allowing it to automatically copy the contents of that directory over to the local /Program Files/ and let the magic happen. The magic always seems to happen, so there's no big issue, there, although it does weird me out somewhat, after many years of .msi installers...
Coming form too many years of VB6 I have a natural inclination to write my own data access code, etc. rather than using database wizard, etc. Same goes for using simple databinding to recordset rather than managing object collections and tying those to controls
I am finally moving to VB.NET and find myself on a solo project without any team on which to lean, so I have a couple related questions as I try to get my head around the transition. The project is basically a line of business app with a SQL Server back end.
1. Are the data designers/wizards so good now that rolling your own is no longer worth while?
2. Is the data-binding now fast, flexible, and reliable?
3. Can you recommend a good book or robust on-line tutorial that covers this sort of programming? 2008 or 2010 preferred.