I am doing the programming on my computer and it works fine-the program, the database itself, inserting to the database is also working fine. But when I publish it and install the program on another computer. It crashes and does not execute the INSERT command.
Here is my code.
Private Sub cmdBlank_Click(sender As System.Object, e As System.EventArgs) Handles cmdBlank.Click
strTariff1 = txtPart1.Text & " " & txtPName1.Text & " " & txtQty1.Text & " " & txtU1.Text
strTariff2 = txtPart2.Text & " " & txtPName2.Text & " " & txtQty2.Text & " " & txtU2.Text
strTariff3 = txtPart3.Text & " " & txtPName3.Text & " " & txtQty3.Text & " " & txtU3.Text
strTariff4 = txtPart4.Text & " " & txtPName4.Text & " " & txtQty4.Text & " " & txtU4.Text
'strTariff5 = txtPart5.Text & " " & txtPName5.Text & " " & txtQty5.Text & " " & txtU5.Text
Call saveToDb()
frmreportax.Show()
End Sub
Private Function saveToDb()
conn.Close()
Dim cmdAdd, cmdCount, cmdAdd2 As New iDB2Command
Dim sqlAdd, sqlCount, sqlAdd2 As String
Dim curr1, curr2, curr3, curr4 As String
Dim count As Integer
conn.ConnectionString = str
conn.Open()
'Check for duplicate entry
sqlCount = "SELECT COUNT(*) AS count FROM cewe WHERE transport=#transport AND blnum=#blnum"
With cmdCount
.CommandText = sqlCount
.Connection = conn
.Parameters.AddWithValue("#transport", frmPart1.txtTransport.Text)
.Parameters.AddWithValue("#blnum", frmPart1.txtNo.Text)
End With
count = Convert.ToInt32(cmdCount.ExecuteScalar())
If count <> 0 Then
MsgBox("Duplicate Entry: " & frmPart1.txtTransport.Text, vbOKOnly + vbExclamation)
Else
sqlAdd = "INSERT INTO cewe (page) " & _
"VALUES (#page) "
With cmdAdd
.Parameters.AddWithValue("#page", Val(frmPart1.txtPage.Text))
.CommandText = sqlAdd
.Connection = conn
.ExecuteNonQuery()
End With
end if
cmdAdd.Dispose()
cmdAdd2.Dispose()
conn.Close()
end function
Please tell me what I am doing wrong? When I run and install the program on my PC, it works perfectly fine. But when I run/install it on another PC, it crashes after the cmdBlank is clicked.
There could be a number of things causing the issue but the first place to look is any error logs or crash report that may give some indication of the problem. Try debugging or logging to get a better picture. Beyond that there are some small suggestions that may help below.
Does the other computer have access to the database you are pointing to? Is the database connection pointing to localhost? In which case you will want to ensure that you have the same credentials (host, username, password, port etc.) set up on the database server on new computer. Are database drivers installed on new computer? What are the fundamental differences between the two machines?
AS400 iSeries DB2 needs to be updated to version 6.xx.0800 and did the tweak!
Installer can be found here
http://www-03.ibm.com/systems/power/software/i/access/windows_sp.html
Problem solved!
Related
OK, so I have a form called quote_guidelines and i would like to use a procedure to update my database with values entered into the quote_guidelines form. The values are the descriptions and costs of decorations, food/drink and entertainment. Each tab has been assigned one of these additional servies. I wanted to make a procedure which would update the database with these new values.
The problem was that the query would have to contain a different table and different textbox names. I tried to solve this by saving the names of the tables and textboxes in variables, which will then be passed into the procedure.
the table variable works fine in the sql statement however, the textbox names dont.
I tried this:
quote_guidelines.Controls(description_textbox).Text
But this doesnt work.
Here is my query:
query = "UPDATE " & additional & " SET description='" & quote_guidelines.Controls("" & description_textbox & "").Text & "', cost= " & quote_guidelines.Controls("" & cost_textbox & "").Text & " WHERE " & additional & "ID='" & y & "'"
When I run the program, i get the following error "An unhandled exception of type 'System.NullReferenceException' occurred in EHCC_BookingSystem.exe
Additional information: Object reference not set to an instance of an object."
I just realised that it might be some other stupid mistake i've made so here's the whole procedure:
Sub UpdateAdditionals(textbox3 As System.Object, textbox4 As System.Object, textbox5 As System.Object, textbox6 As System.Object, textbox7 As System.Object, textbox8 As System.Object, ByRef additional As String, ByRef description_textbox As String, ByRef cost_textbox As String)
mysqlconn = New MySqlConnection
mysqlconn.ConnectionString = "Server=localhost;userid=root;password=root;database=comp4"
Dim reader As MySqlDataReader
MsgBox(additional & description_textbox & cost_textbox)
Try
mysqlconn.Open()
Dim query As String
query = "UPDATE " & additional & " SET description='" & quote_guidelines.Controls.Find(description_textbox, True).FirstOfDefault().Text & "', cost= " & quote_guidelines.Controls.Find(cost_textbox, True).FirstOfDefault().Text & " WHERE " & additional & "ID='" & y & "'"
MsgBox(query)
command = New MySqlCommand(query, mysqlconn)
reader = command.ExecuteReader()
mysqlconn.Close()
Catch ex As MySqlException
MessageBox.Show(ex.Message)
Finally
mysqlconn.Dispose()
End Try
End Sub
Try this - Replaced Controls in Controls.Find (Note the `True parameter to search the controls children):
query = "UPDATE " & additional & " SET description='" & TryCast(quote_guidelines.Controls.Find(description_textbox, True)(0), TextBox).Text & "', cost= " & TryCast(quote_guidelines.Controls.Find(cost_textbox, True)(0).Text & " WHERE " & additional & "ID='" & y & "'"
Also note you could do .FirstOfDefault() to get the first control (don't forget to cast):
Controls.Find("nameofcontrol", True).FirstOfDefault()
I'm working in a small SQL Database program. The programs just there to view, edit and update the database records. Everything is working remarkably well considering I've never tried something like this before. I've managed to get the Add Records, Refresh Records and Delete Records functions working flawlessly. However, I've hit a little bump when trying to UPDATE a selected record.
To clarify, the SQL Table is displayed in a list view, from this list view the end-user can select a particular-record and either edit or delete it.
The edit button opens a new form window with text fields which are automatically filled with the current information of that record.
The code for the edit record form is:
Private Sub frmEdit_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
intDB_ID_Selected = CInt(frmMain.lvRec.SelectedItems(0).Text)
Call dispCaption()
Call dispInfo() 'Display the info of the selected ID
End Sub
Private Sub dispInfo()
SQL = "Select * from PersonsA " & _
"where Members_ID=" & intDB_ID_Selected & ""
With comDB
.CommandText = SQL
rdDB = .ExecuteReader
End With
If rdDB.HasRows = True Then
rdDB.Read()
Me.midtxt.Text = rdDB!Members_ID.ToString.Trim
Me.gttxt.Text = rdDB!Gamer_Tag.ToString.Trim
Me.sntxt.Text = rdDB!Screenname.ToString.Trim
Me.fntxt.Text = rdDB!First_Name.ToString.Trim
Me.lntxt.Text = rdDB!Last_Name.ToString.Trim
Me.dobtxt.Text = rdDB!DoB.ToString.Trim
Me.dobtxt.Text = rdDB!DoB.ToString.Trim
Me.emailtxt.Text = rdDB!E_Mail_Address.ToString.Trim
Me.teamptxt.Text = rdDB!Position.ToString.Trim
Me.ugctxt.Text = rdDB!Cautions.ToString.Trim
Me.recordtxt.Text = rdDB!Record.ToString.Trim
Me.eventatxt.Text = rdDB!Event_Attendance.ToString.Trim
Me.Mstattxt.Text = rdDB!Member_Status.ToString.Trim
End If
rdDB.Close()
End Sub
Private Sub dispCaption()
End Sub
Private Sub cmdUpdate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdUpdate.Click
Call disControl()
'Validation
If invalidUpdateEntry() = True Then
Call enaControl()
Exit Sub
End If
'Prompt the user if the record will be updated
If MsgBox("Are you sure you want to update the selected record?", CType(MsgBoxStyle.YesNo + MsgBoxStyle.DefaultButton2 + MsgBoxStyle.Question, MsgBoxStyle), "Update") = MsgBoxResult.Yes Then
'Update query
SQL = "Update PersonsA" & _
"SET Members_ID='" & Me.midtxt.Text.Trim & "'," & _
"Gamer_Tag='" & Me.gttxt.Text.Trim & "'," & _
"Screenname='" & Me.sntxt.Text.Trim & "'," & _
"First_Name='" & Me.fntxt.Text.Trim & "'," & _
"Last_Name='" & Me.lntxt.Text.Trim & "'," & _
"DoB='" & Me.dobtxt.Text.Trim & "'," & _
"E_Mail_Address='" & Me.emailtxt.Text.Trim & "'," & _
"Position='" & Me.teamptxt.Text.Trim & "'," & _
"U_G_Studio='" & Me.ugptxt.Text.Trim & "'," & _
"Cautions='" & Me.ugctxt.Text.Trim & "'," & _
"Record='" & Me.recordtxt.Text.Trim & "'," & _
"Event_Attendance='" & Me.eventatxt.Text.Trim & "'," & _
"Member_Status='" & Me.Mstattxt.Text.Trim & "'" & _
"WHERE Members_ID='" & intDB_ID_Selected & "'"
Call execComDB(SQL) 'Execute the query
Me.Close()
'*** Refresh the list
SQL = "Select * from PersonsA "
Call frmMain.dispRec(SQL)
'--- End of refreshing the list
Exit Sub
Else
Call enaControl()
End If
End Sub
As I've said, I've been able to do everything else using an extremely similar method, but when I try to UPDATE the record I get an error saying
An unhandled exception of type 'System.Data.SqlClient.SqlException' occurred in System.Data.dll
Additional information: Incorrect syntax near 'Members_ID'.
I know it's this line that's the problem
"WHERE Members_ID='" & intDB_ID_Selected & "'"
Call execComDB(SQL) 'Execute the query
But referencing 'intDB_ID_Selected' has always worked before, and it's been set-up on the update form records load as intDB_ID_Selected = CInt(frmMain.lvRec.SelectedItems(0).Text)
I know this is a huge thread but if anyone could steer me in the right direction WITHOUT telling me to re-write the entire statement I'd be forever grateful.
EDIT1: I fixed the comma before the WHERE clause, but I'm still getting the same error.
Missing a space between
"Update PersonsA " & _
"SET Members_ID= ....
and (as already pointed out) a comma not needed before the WHERE
Said that, do a favor to yourself and to your users. Do not use string concatenation to build a sql command. Use always a parameterized query.
Just as an example
SQL = "Update PersonsA SET Members_ID=#id, Gamer_Tag=#tag, Screenname=#screen," & _
"First_Name=#fname,Last_Name=#lname,DoB=#dob,E_Mail_Address=#email," & _
"Position=#pos,U_G_Studio=#studio,Cautions=#caution,Record=#rec," & _
"Event_Attendance=#event, Member_Status=#stat " & _
"WHERE Members_ID=#id"
SqlCommand cmd = new SqlCommand(SQL, connection)
cmd.Parameters.AddWithValue("#id", Me.midtxt.Text.Trim)
..... so on for the other parameters defined above ....
cmd.ExecuteNonQuery();
Change "Member_Status='" & Me.Mstattxt.Text.Trim & "'," & _
to "Member_Status='" & Me.Mstattxt.Text.Trim & "'" & _
Looks like it was just an extra rogue comma!
On any error like this, use debugging provided with Visual Studio. Inspect the value of SQL, paste into MS SQL Management Studio - it has syntax highlight, and you should be able to spot the error easily.
To prevent further issues (including SQL injection vulnerability), separate this query into an embedded resource, and use parameters. Then it's easy to view, maintain (you can copy/paste between SQL Mgmt Studio and VS), and ultimately use it in code.
A side note, you don't need to use Call in VB.NET, just put a method name with parenthesis.
i am facing very strange problem , I am using the following piece of code but ds is not filled some times there is data in the ds but not always, I have change the connection pool and also restart the iis but no luck at all , I am not able to find where the problem is please help me out.
I am running the same query in the TOAD and its giving result , I have also commit the transaction for if any thing in inconsistent.
Dim command As New OracleCommand
Dim ds As New DataSet
Try
Using connection As New OracleConnection
(ConfigurationManager.ConnectionStrings("CA").ConnectionString.ToString())
connection.Open()
command.Connection = connection
command.CommandText = "SELECT w.portfolio, w.appl_group,
tm.trng_title, p.tt_program_title," & _
" p.created_date,
p.tt_target_completion_date, p.tt_prog_status," & _
" w.emp_id, w.first_name || ' ' ||
w.last_name, ('Y') training_done_flag," & _
" t.actual_completion_date,
p.created_by, w.people_manager, " & _
" w.project_manager, w.flag" &
_
" FROM tt_training_done_records t," & _
" wsr_employee w, " & _
" tt_training_master tm, " & _
" tt_newprogram p" & _
" WHERE(w.emp_id = t.employee_id)" & _
" AND t.training_info_id = tm.trng_id"
& _
" AND p.tt_program_id(+) =
t.program_id" & _
" AND tm.trng_id IN ( 'TT_009' ) " & _
" AND t.actual_completion_date BETWEEN
TO_DATE('11-Mar-2009') AND TO_DATE('11-Mar-2013') " & _
" "
Dim adpt As New OracleDataAdapter(command)
adpt.AcceptChangesDuringFill = False
adpt.Fill(ds)
connection.Close()
End Using
Don't rely on the default behavior of casting a string into a date. Either use a date literal or provide the format string argument. This introduces a dependency on NLS environment settings your .NET code should not depend upon.
Instead of TO_DATE('11-Mar-2013')
Try date '2013-03-11' or TO_DATE('11-Mar-2013'), 'DD-Mon-YYYY')
VB.NET 2.0:
I'm issuing a backup command to a SQL server from a VB.NET application. I'm capturing the messages it sends out and appending them to a multiline textbox.
What I'm trying to do, though, is to allow the application to keep responding to GUI control events (mainly so that the user can resize the output window or cancel the backup). So I use BeginExecuteReader and spin in a loop with Application.DoEvents(). But it seems that as soon as the backup starts issuing its print statements, I get IAsyncResult.IsCompleted = True and it drops down to EndExecuteReader, and the GUI is now locked up again. How can I get it to stay in the loop until the backup command completes and yet still get those output statements and keep the GUI responsive? Thanks.
Here's my code:
' Enable retrieve print statements from the server'
AddHandler oConn.InfoMessage, AddressOf LogToBufferHandler
strSQL &= vbNewLine & "begin try"
strSQL &= vbNewLine & " declare #BackupName as varchar(255)"
strSQL &= vbNewLine & " declare #BackupDesc as varchar(255)"
strSQL &= vbNewLine & " declare #backupTime as varchar(50)"
strSQL &= vbNewLine & " set #backupTime = (select convert(datetime, getdate(), 100))"
strSQL &= vbNewLine & " set #BackupName = (SELECT '[' + db_name() + '] Full Backup')"
strSQL &= vbNewLine & " set #BackupDesc = (SELECT 'Automated full backup of [' + db_name() + '] on ' + #backupTime + '.')"
strSQL &= vbNewLine & " "
strSQL &= vbNewLine & " BACKUP DATABASE [#Database#]"
strSQL &= vbNewLine & " TO DISK = #BackupFullPath"
strSQL &= vbNewLine & " WITH stats,"
strSQL &= vbNewLine & " NAME = #BackupName,"
strSQL &= vbNewLine & " DESCRIPTION = #BackupDesc;"
strSQL &= vbNewLine & " select [IsSuccessful] = 1"
strSQL &= vbNewLine & " end try"
strSQL &= vbNewLine & " begin catch"
strSQL &= vbNewLine & " SELECT [IsSuccessful] = 0"
strSQL &= vbNewLine & " end catch"
'Workaround: Backup Database requires the name of the object, not a string'
' and I dont want to use dynamic SQL.'
strSQL = strSQL.Replace("#Database#", sb.InitialCatalog)
oConn.Open()
oCmd = New SqlCommand()
oCmd.Connection = oConn
oCmd.CommandText = strSQL
oCmd.CommandType = CommandType.Text
oCmd.Parameters.AddWithValue("#BackupFullPath", backupFullPath)
oCmd.CommandTimeout = 60 * 5
'Spin until complete, cancel, or timeout'
Dim result As IAsyncResult = oCmd.BeginExecuteReader(CommandBehavior.CloseConnection)
While Not result.IsCompleted
Application.DoEvents()
If blnCancel Then
oCmd.Cancel()
End If
System.Threading.Thread.Sleep(50)
End While
Try
oDataReader = oCmd.EndExecuteReader(result)
oDataTable.Load(oDataReader)
'Get results'
' (unfourtunately, you cannot do BeginExecuteScalar ASync in .Net 2.0,'
' so we are using a DataTable first column, row)'
If oDataTable IsNot Nothing _
AndAlso oDataTable.Rows.Count > 0 _
AndAlso oDataTable.Columns.Contains("IsSuccessful") _
AndAlso oDataTable.Rows(0).Item("IsSuccessful") = 1 Then
eBackupResult = BackupStatus.Succeeded
returnPath = backupFullPath 'Only set return path if the backup succeeded'
Else
eBackupResult = BackupStatus.Failed
End If
Catch ex As Exception
If Not ex.Message.Contains("cancelled by user") Then Throw ex
eBackupResult = BackupStatus.Canceled
End Try
Polling loops (DoEvents) are considered evil for many reasons. It is probably the easiest way for you to switch to BackgroundWorker and abandon the nasty Begin-poll-End scheme.
If you want to keep it, here is the bug: Accepting the reader can be quick but that doesn't mean that all results have arrived (let me illustrate: what if you had queried 1TB of data? - reading that is a long process). You need to Read in an async (polling) way too. Now the thing gets out of hand. Just abandon it.
In other words, oDataTable.Load is blocking which is hard to fix.
You can use TASKS for this. A task is similar in concept to a thread. By putting your code into a task the main thread can continue to run (which is the thread that takes user input and responds to resize commands).
Here's an article that talks more about tasks and has a VB.NET example.
http://www.dotnetcurry.com/ShowArticle.aspx?ID=491
Have fun!
BackGroundWorker and ReportProgress
BackgroundWorker Class
I'm trying to use a VB button to insert data into a database, but it keeps bringing up the error message I have in place for exceptions.
Can anyone help me with why this does not update the database?
Protected Sub Button1_Click(sender As Object, e As System.EventArgs) Handles Button1.Click
Dim connetionString As String
Dim sqlCnn As SqlConnection
Dim sql As String
Dim adapter As New SqlDataAdapter
Dim Customer As String = TextBox1.Text
Dim Product As String = TextBox2.Text
Dim Location As String = TextBox3.Text
Dim Details As String = TextBox4.Text
Dim Owners As String = DropDownList1.Text
Dim Urgency As String = DropDownList2.Text
connetionString = "Data Source=ZUK55APP02;Initial Catalog=BugFixPortal;User ID=SLC***;Password=rep***"
sql = "INSERT INTO Requests (Owner, Customer, Product, Location, Urgency, Details) VALUES ('" & Owners & ", " & Customer & ", " & Product & ", " & Location & ", " & Urgency & ", " & Details & "')"
sqlCnn = New SqlConnection(connetionString)
Try
sqlCnn.Open()
adapter.UpdateCommand = sqlCnn.CreateCommand
adapter.UpdateCommand.CommandText = sql
adapter.UpdateCommand.ExecuteNonQuery()
sqlCnn.Close()
Catch ex As Exception
MsgBox("Unable to update Database with Request - Please speak to Supervisor!")
End Try
End Sub
I would not go down this road as your code is weak against SQL Injection
you should use parameters instead.Something like the below
c.Open();
string insertString = #"insert into YourTable(name, street, city,....) values(#par1, #par2, #parN,....)"
SqlCommand cmd = new SqlCeCommand(insertString, c);
cmd.Parameters.Add("#par1", SqlDbType.VarChar).Value = "MyName";
//etc
cmd.ExecuteNonQuery();
c.Close();
You are incorrectly quoting your values.
This string has an opening and closing single quote around ALL the values, which is incorrect.
VALUES ('" & Owners & ", " & Customer & ", " & Product & ", " & Location & ", " & Urgency & ", " & Details & "')"
Instead, put single quotes around character data, eg., if Product is a varchar, it would look like this:
VALUES (" & Owners & ", " & Customer & ", '" & Product & "', " & Location & ", " & Urgency & ", " & Details & ")"
The real problem, though, is that you should be using parameterized queries instead. This code is prone to SQL injection attacks.
Change this;
MsgBox("Unable to update Database with Request - Please speak to Supervisor!")
to Something like this;
MsgBox("Unable to update Database with Request - Please speak to Supervisor!" & ex.Message)
It will give you more details on the exception, however at a quick glance I can see a problem, the values you are trying to insert are strings, you've enclosed all your values in a single set of ' characters, rather than enclosing each string parameter in a pair of ' values, i.e.
sql = "INSERT INTO Requests (Owner, Customer, Product, Location, Urgency, Details) VALUES ('" & Owners & "', '" & Customer & "', '" & Product & "',' " & Location & "', '" & Urgency & "', '" & Details & "')"
You really should look at parameterizing your queries as you're wide open to SQL injection attacks. See HERE
In terms of your code itself, your SQL syntax is wrong as you need to put apostrophes around each value. Try this:
sql = "INSERT INTO Requests (Owner, Customer, Product, Location, Urgency, Details)
VALUES ('" & Owners & "', '" & Customer & "', '" & Product &
"', '" & Location & "', '" & Urgency & "', '" & Details & "')"
Here's an example using Parameters
sql = "INSERT INTO Requests (Owner, Customer, Product, Location, Urgency, Details)
VALUES ('#Owners', '#Customer', '#Product', '#Location', '#Urgency', '#Details')"
Then add parameters like so:
command.Parameters.AddWithValue("#Owners", Owners)
command.Parameters.AddWithValue("#Customer", Customer)
command.Parameters.AddWithValue("#Product", Product)
command.Parameters.AddWithValue("#Location", Location)
command.Parameters.AddWithValue("#Urgency", Urgency)
command.Parameters.AddWithValue("#Details", Details)
I think you want to use adapter.InsertCommand instead of adapter.UpdateCommand
in
Try
sqlCnn.Open()
adapter.UpdateCommand = sqlCnn.CreateCommand //(adapter.InsertCommand)
adapter.UpdateCommand.CommandText = sql //(adapter.InsertCommand)
adapter.UpdateCommand.ExecuteNonQuery() //(adapter.InsertCommand)
sqlCnn.Close()
Catch ex As Exception
MsgBox("Unable to update Database with Request - Please speak to Supervisor!")
End Try
and agree with parametrized sql query
see http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqldataadapter.aspx for more infos