I'm currently working on a project for school and it includes a login and register system.
This is a function that I have made. The "taken" variable will be passed back to the main program.
Dim taken As Boolean
Dim temp As String
For counter = 1 To totalrecords
FileGet(1, player_info)
temp = player_info.username
If TextBox2.Text = temp Then
msgbox("this is a messagebox")
taken = True
End If
Next
This is the part of the code that checks if any usernames are in use. If so, taken = true and then a message is displayed.
Now, for some reason the if statement part is not being carried out. The message box does not show at all. I have tested this by using more than one same username and the second (same) username is still added to the file. I'm very confused.
Part I believe is not working -
If TextBox2.Text = temp Then
taken = True
End If
You should use String.Equals(String1, String) to compare TextBox text and the temp variable.
In your case it should be written as this.
If String.Equals(TextBox2.Text, temp) Then
taken = true
End if
Related
Short version
I'm entering information in a database and fetching it shortly after, but for some reason, when I enter the information, it isn't immediately entered, so that when I try to fetch it, I get old results. Why does this happen? I thought the operations were synchronous.
Long version
I have a split Access database. At the moment the backend is on my own hard drive to speed up testing, eventually this backend will land on a server. Back when it was a combined frontend/backend database and before I had done a major code refactor (tbh, it was quite the clusterfornication before that), and now this is happening in a number of different scenarios, but pretty much every time I enter information and try to fetch it right after that. Why this happens is a mystery to me, since everything I was reading told me there is no multi-threading in VBA and that everything is synchronous if not specified otherwise, and I haven't enabled any asynchronous options.
Two Examples:
I add a record to the database then refresh the form that contains those new records. I'm not going to post the full code (unless it is deemed necessary), since I've modularized the code a lot. But essentially it boils down to this: the user clicks a button which executes this:
Private Sub Anhang_hinzufügen_Click()
If IsNull(Me.Parent.ID) Then
MsgBox "Bitte erst Felder ausfüllen, und anschließend Anhänge hinzufügen", vbInformation
Else
AnhängeAuswählen Me.Parent.Name, Me.Parent.ID
Me.Form.Requery
End If
End Sub
As part of the AnhängeAuswählen method, the method AddRecord is called:
Function AddRecord(TableName As String, fields() As String, values) As Long
Dim Table As DAO.Recordset
Set Table = LUKSVDB.OpenRecordset(TableName)
Table.AddNew
For i = LBound(fields) To UBound(fields)
If TypeName(Table.fields(fields(i)).Value) = "Recordset2" Then
Dim rs2 As DAO.Recordset2
Set rs2 = Table.fields(fields(i)).Value
If IsArray(values(i)) Then
For j = LBound(values(i)) To UBound(values(i))
rs2.AddNew
rs2!Value = values(i)(j)
rs2.Update
Next j
Else
rs2.AddNew
rs2!Value = values(i)
rs2.Update
End If
Else
Table.fields(fields(i)) = values(i)
End If
Next i
AddRecord = Table!ID
Table.Update
Table.Close
End Function
The record is created, that's not the problem. But when it executes Me.Form.Requery, the new record doesn't appear in the form. Only when I execute Me.Form.Requery a fraction of a second later does the record appear.
I add a record to the database using a form, update some information in the recordset with VBA, then requery the subreport with the records. The record appears immediately, but the details I added programmatically only appear when I execute Me.Parent.Requery a couple of seconds later.
The first form is a data entry form, so that as soon as the data is saved, it's blank in order to create a new record. The previous should then appear in the form. The button to create the new record looks like this:
Private Sub Anmerkung_Hinzufügen_Click()
currentID = Me.ID
mSaved = True
If Me.Dirty Then Me.Dirty = False
UpdateRecord "Anmerkungen", currentID, StringArray("Person", "Datum"), Array(User, Now)
Me.Parent.Requery
End Sub
The UpdateRecord is similar to the AddRecord method:
Function UpdateRecord(TableName As String, ByVal ID As Integer, fields() As String, values)
Dim Table As DAO.Recordset
Set Table = SeekPK(TableName, ID, True)
Table.Edit
For i = LBound(fields) To UBound(fields)
If TypeName(Table.fields(fields(i)).Value) = "Recordset2" Then
Dim subtable As DAO.Recordset2
Set subtable = Table.fields(fields(i)).Value
If IsArray(values(i)) Then
On Error Resume Next
Dim t
t = LBound(values(i))
If Developer Then On Error GoTo -1 Else On Error GoTo Fehler
If Err.Number = 0 Then
For j = LBound(values(i)) To UBound(values(i))
subtable.AddNew
subtable!Value = values(i)(j)
subtable.Update
Next j
End If
Else
subtable.AddNew
subtable!Value = values(i)
subtable.Update
End If
Else
Table.fields(fields(i)) = values(i)
End If
Next i
Table.Update
Table.Close
End Function
Does anyone know why this happens, and how I can prevent it? I could do a bit of a workaround with timers on the forms, so that it refreshes the form a couple of seconds later, but that seems like a kludgy workaround to me, especially considering I don't know how long it specifically takes, and the times could change drastically once the backend is on the server.
Additional information, in case it's necessary:
In the code I've posted I've removed some additional code for error handling and performance logging, but it doesn't have any impact on what's happening otherwise.
When the database is opened, a global variable LUKSVDB As DAO.Database is initialized:
Function ConnectDatabase(Backend As Integer)
Select Case Backend
Case 0: DatenOrt = 'redacted, folder in which the production/beta database is located on the server
Case 1: DatenOrt = 'redacted, folder in which I have a personal testing database on the server
Case 2: DatenOrt = 'redacted, folder in which I have the testing database on my own computer
End Select
Set LUKSVDB = OpenDatabase(DatenOrt & "\LUKS-Verwaltung_be.accdb", False, False, ";pwd=PASSWORD")
End Function
For testing purposes, ConnectDatabase is launched with a value of 2. However, if it's a problem on my own SSD, where latency is just about 0, then I can only assume it will be a problem on the server as well, where the latency is definitely not 0.
Copy this into Visual Studio, add a textbox and it'll run.
Const NET_FW_ACTION_ALLOW = 1
Dim fwPolicy2 = CreateObject("HNetCfg.FwPolicy2")
Dim RulesObject = fwPolicy2.Rules
For Each rule In RulesObject
If rule.action = NET_FW_ACTION_ALLOW Then
TextBox1.Text += rule.name & vbnewline
End If
Next
This is an example of what I get but I only need each app to be listed once, not two times. What am I doing wrong or why does it behave like this?
qBittorrent
qBittorrent
Chrome
Chrome
Visual Studio
Visual Studio
and so on...
It behaves like this because rule.Name is not a unique identifier for a firewall rule. The same rule name may be used for different protocols (TCP, UDP), profiles (domain, private, public), direction (in, out), etc. If you are only interested in rule.Name, add them to a set, then print that set, as follows.
Const NET_FW_ACTION_ALLOW = 1
Dim fwPolicy2 = CreateObject("HNetCfg.FwPolicy2")
Dim RulesObject = fwPolicy2.Rules
Dim names As New HashSet(Of String)
' Create set of unique names.
For Each rule In fwPolicy2.Rules
If rule.action = NET_FW_ACTION_ALLOW Then
names.Add(rule.name)
End If
Next
' Add names to TextBox.
For Each name As String In names
TextBox1.Text += name & vbNewLine
Next
For Each rule In RulesObject
If rule.action = NET_FW_ACTION_ALLOW AndAlso TextBox1.Text.Contains(rule.name.ToString) = False Then
TextBox1.Text += rule.name & vbnewline
End If
Next
The above is one way to do it. It simply checks whether it's already added to the textbox. Btw, I don't know offhand whether or not rule.name is already a string so I added .ToString; if it's already a string, you don't need to add that.
Also, most of us would recommend using Option Strict, and declaring your variables as a type. i.e. Dim myVar as String = "some string"
I am using bool method with Visual Studio 2015 and SQL Server 2005.
When I am passing correct details and click loginButton, the code always returns false from the stored procedure.
This is my stored procedure in SQL Server 2005:
ALTER PROCEDURE [dbo].[UserCheckLoginDetails]
(#IsLoginIdCorrect BIT OUTPUT,
#IsPasswordCorrect BIT OUTPUT,
#LoginID NVARCHAR(200),
#Password NVARCHAR(20)
)
AS
BEGIN
SET #IsLoginIdCorrect = 0
SET #IsPasswordCorrect = 0
IF EXISTS (SELECT * FROM UserInfo
WHERE loginid = #LoginID AND password = #Password)
BEGIN
SET #IsLoginIdCorrect = 1
SET #IsPasswordCorrect = 1
END
ELSE
IF EXISTS (SELECT * FROM UserInfo WHERE loginid = #LoginID)
BEGIN
SET #IsLoginIdCorrect = 1
END
END
This is my method returning True or False:
Private Sub GetIsUserLoginCorrect(IsLoginIdCorrect As Boolean, IsPasswordCorrect As Boolean)
Using Conn As New SqlConnection(_SqlCon)
Using cmd As New SqlCommand("UserCheckLoginDetails", Conn)
cmd.CommandType = CommandType.StoredProcedure
Conn.Open()
'OutPut Parameters
cmd.Parameters.Add("#IsLoginIdCorrect", SqlDbType.Bit).Direction = ParameterDirection.Output
cmd.Parameters.Add("#IsPasswordCorrect", SqlDbType.Bit).Direction = ParameterDirection.Output
'InPut Parameters
cmd.Parameters.AddWithValue("#LoginID", LoginIDTextBox.Text)
cmd.Parameters.AddWithValue("#Password", PasswordTextBox.Text)
cmd.ExecuteNonQuery()
' Assign Parameters
IsLoginIdCorrect = Convert.ToBoolean(cmd.Parameters("#IsLoginIdCorrect").Value)
IsPasswordCorrect = Convert.ToBoolean(cmd.Parameters("#IsPasswordCorrect").Value)
End Using
End Using
End Sub
This is the Login button click event handler, even when I provide the correct values, it still always returns false:
Private Sub LoginButton_Click(sender As Object, e As EventArgs) Handles LoginButton.Click
Try
Dim IsLoginIdCorrect, IsPasswordCorrect As Boolean
GetIsUserLoginCorrect(IsLoginIdCorrect, IsPasswordCorrect)
If IsLoginIdCorrect And IsPasswordCorrect = True Then
Me.Hide()
' User Information
DeshBoard.MainUserIdLabel.Text = Me.MainUserIdLabel.Text
DeshBoard.UserNameLabel.Text = Me.UserNameLabel.Text
DeshBoard.UserLoginIdLabel.Text = Me.UserLoginIdLabel.Text
DeshBoard.UserLevelLabel.Text = Me.UserLevelLabel.Text
'Organanization Information
DeshBoard.MainOrgIDLabel.Text = Me.MainOrgIDLabel.Text
DeshBoard.OrgNameLabel.Text = Me.OrgNameLabel.Text
DeshBoard.OrgTelLabel.Text = Me.OrgTelLabel.Text
DeshBoard.OrgEmailLabel.Text = Me.OrgEmailLabel.Text
DeshBoard.OrgAddressLabel.Text = Me.OrgAddressLabel.Text
DeshBoard.Show()
Else
If IsLoginIdCorrect = False Then
MessageBox.Show("Login ID is not correct...!!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
LoginIDTextBox.Clear()
PasswordTextBox.Clear()
LoginIDTextBox.Focus()
Else
MessageBox.Show("Password ID is not correct...!!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
PasswordTextBox.Clear()
PasswordTextBox.Focus()
End If
End If
Catch ex As ApplicationException
MessageBox.Show("Error: " + ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
End Try
End Sub
Thank you very much.
You need to add ByRef to both arguments in Sub GetIsUserLoginCorrect().
To demonstrate, try the following with and without ByRef.
Private Sub ChangeBoolean(ByRef TorF As Boolean)
TorF = True
End Sub
Private Sub OPCode2()
Dim TorF As Boolean
ChangeBoolean(TorF)
Debug.Print(TorF.ToString) ' Result False without ByRef in ChangeBoolean
'When ByRef is added result is True
End Sub
First off, a method can refer to either a sub or a function. A sub is a method that performs an action. A function is a method that calculates or retrieves one or more values.
A sub should not be called Getxxx, because its primary purpose should not be returning a value.
A function should be used to return values. Since you are trying to retrieve multiple values, if you were using 2017 I would suggest returning a named tuple with your two values, since you aren’t I would create an object that has the values and return that.
On a totally different note, you really can’t tell the difference between right user wrong password and wrong user right password and wrong user wrong password - so you shouldn’t tell someone you can. You just say login unsuccessful login, or invalid username/password combination.
There's a lot wrong with your code.
Firstly, why are you using so much of SQL code ? Correct me if i am wrong : You are trying to build a log in system. So much of SQL code or even the stored procedure is worthless here. You can simply write the SQL statements in your code by using the SqlCommand class. Even though you are using the ALTER PROCEDURE statement, i can surely say that things can be simplified here.
You are also using the Me keyword. It's not C# where the use of this(same as Me in VB.Net) becomes compulsory. I assume it's a Windows Forms Application and if that's so, then using Me keyword to access it's child elements wouldn't result in any different if it's not used at all.
The next worth mentioning issues is your Name Conventions. Most or should i say all of your variables have the same name. For example : IsLoginIdCorrect - used both as a parameter of a method and also a variable inside a method.
The next issues is in these two lies :
Dim IsLoginIdCorrect, IsPasswordCorrect As Boolean
GetIsUserLoginCorrect(IsLoginIdCorrect, IsPasswordCorrect)
You are passing the boolean variables before they have been assigned any value. You are lucky it's not C# or this wouldn't even compile. Passing the boolean variables without assigning any value will, by default, set their values to False. So, literally, you are always passing the same value in which case, the outcome will always be the same.
The next issue is in your If statement inside your LoginButton_Click method aka LoginButton's click event handler's method :
If IsLoginIdCorrect And IsPasswordCorrect = True Then
The if statements, if described in simple words, means : If IsLoginIdCorrect and IsPasswordCorrect are true, then proceed.... So, in this case, IsPasswordCorrect = True doesn't affect much. However, this is not the best practice too. You should better follow the following coding rule while using If statements:
If (IsLoginIdCorrect = True AndAlso IsPasswordCorrect = True) Then
AndAlso operators evaluates each side just like the And operator. The difference is that it would return False if the left side(IsLoginIdCorrect, in this case) returns False.
The next issues is the usage of ApplicationException. I don't understand why, in this era, you are using that class! This class is usually used to derive from and create exceptions. You can simply use Exception instead of ApplicationException.
Your Try-Catch block seems not useful as well. All of your codes inside the LoginButton_Click are in If conditions and they perform very basic operation. It is unlikely to ever throw any exception at all.
Your logics, for most part, are illogical(sorry to put it this way). In your GetIsUserLoginCorrect method, you are setting IsLoginIdCorrect and IsPasswordCorrect to either true or false but it wouldn't matter because they are parameters of the method itself. So even if you set their values, they will be reset when you call the method again. The reason why ByRef (according to Mary's answer) works is because ByRef, in short, means that you are pointing to original variable that you passed(not it's copy).
And finally, the solution you are looking for....
Even though i see you have marked Mary's answer as the answer, i would like to help you out a bit as-well.
Firstly, get rid of the stored procedure if possible and also if you are not using it anywhere else. I see you are using the If Exist condition inside your SQL queries. This is actually a nice move because according to performance reports, checking if data exists in a database/table using IF EXISTS yields the fastest output. So bravo for that one. But if you follow my advice and want to ditch the stored procedure, then you need to get rid of the IF EXISTS statement as well. Rather, you can simply use the SELECT statement itself, use the ExecuteScalar method of the SqlCommand class, convert it's value to Integer and check if the value of the Integer is 1 or not.
Example :
Dim cmd = New SqlCommand("SELECT COUNT(*) FROM UserInfo
WHERE loginid = #LoginID AND password = #Password")
Dim Exists = Convert.ToInt32(cmd.ExecuteScalar)
If Exists = 1 Then
''Code if data exists
End if
Note that i have used Convert.ToInt32 here. This will prevent null-reference exception as when ExecuteScalar returns Null, it will be converted to 0 integer value.
Also, why are you using GetIsUserLoginCorrect as method ? You can simply use it as a function and return required values. As you are returning multiple values, you can easily use the Tuple type as your function's type:
Private Function GetIsUserLoginCorrect(IsLoginIdCorrect As Boolean, IsPasswordCorrect As Boolean) As Tuple(of Boolean, Boolean)
....
....
return Tuple.Create(IsLoginIdCorrect, IsPasswordCorrect)
End Sub
Usage
Dim IsLoginCorrect = GetIsUserLoginCorrect(first_boolean_variable,second_boolean_variable).Item1
Dim IsPasswordCorrect = GetIsUserLoginCorrect(first_boolean_variable,second_boolean_variable).Item2
One last thing. As you are showing DeshBoard form after hiding the main form, make sure to call MainForm.Close on the Dashboard form's Closing/Closed event. This will ensure the application's exit(unless you have other plans for the main form, of course).
Hope this answer helps you.
I am new to MS Access and I am trying to create a simple Macro with a call to VBA code.
the VBA code here is a sample (which also doesn't run)
Public Function RunImport()
Dim N As Integer
Dim Message1, Message2, Title, Default1, Default2, JulianSD, JulianED
Message1 = "Enter Julian Start Date"
Message2 = "Enter Julian End Date"
Title = "User Input Section"
Default1 = "17365"
Default2 = "17000"
JulianSD = InputBox(Message1, Title, Default1)
JulianED = InputBox(Message2, Title, Default2)
End Function
do you think you might be able to locate an issue here?
Thanks!
PS. I am using Version 14.0.7177.500 (32-bit). it wasn't my choice.. (if it were, I wouldn't be using access.. :p)
The most common use of a function is to return a value or values. Your function does not appear to be returning any value. At the end of a function you would normally have a line of code that says what value the function will return, for example....
RunImport = JulianSD - JulianED
End Function
A line like this would usually be inserted before the 'End Function' line. However if your intention is not to return a value, but instead you just want to run a vba macro, perhaps you need to change your function to a Sub routine...
Public Sub RunImport()
'code goes here
End Sub
after finding many useful answers on this site from others' questions I am now in a position where I need to ask my own question as can't seem to find a similar issue elsewhere...
I am working on a Windows Form project in VB.net. I have many text boxes which require data validation. Therefore, I am storing the limits for the text box values in a seperate xml file and the below code runs on the validating event of each text box. This has worked fine up until now....
I have tried to include more text boxes and subsequently edited the xml file (importing to MS Access then exporting back to overwrite the original xml file). Now, when debugging, I see the updated datatable has been loaded/read correctly from the xml but the ToString.Contains returns False when it should return True. Its as if the string is not being recognised correctly in the Datatable. I really can't think what is causing this as it was working perfectly well before trying to add more text boxes. Any help would be very gratefully received?!!
For Each row As DataRow In data.dtLimits.Rows
If row(1).ToString.Contains(tb.Name) Then
ul = Double.Parse(row(2).ToString)
ll = Double.Parse(row(3).ToString)
If IsNumeric(tb.Text) Then
If Double.TryParse(tb.Text, value) Then
If value > ul Or value < ll Then
e.Cancel = True
tb.Select(0, tb.Text.Length)
ErrorProvider1.SetError(tb, "Please enter a value between " & row(3).ToString & " And " & row(2).ToString)
End If
End If
ElseIf tb.Text = "" Then
tb.Text = 0
e.Cancel = False
Else
e.Cancel = True
tb.Select(0, tb.Text.Length)
ErrorProvider1.SetError(tb, "Please enter a valid datum")
End If
End If
Next
NB- The data table has four columns 0-ID Value, 1-Textbox Name,2-Upper Limit,3-Lower Limit.