HOW TO IMPLEMENT A LOGIN FORM IN VB6

Before anything else, I will assume that you have previous knowledge with regards to constructing basic SQL commands using MS Access. This tutorial will demonstrate how to create a login form in Visual Basic 6.0 using MS Access as database engine.

To get us started, we need to create a new table to our database. Name it ‘Users’, with the following structure:

FIELD NAME	DATA TYPE	ATTRIBUTES
ID	AutoNumber
Username	Text	Field Size: 15
Password	Text	Field Size: 255 | Input Mask:*

The structure is pretty straight forward. The ID field is Auto Incremented and will serve as the Primary Key. The Username is of type Text with the length of 15 characters long. Finally, the Password field 255 in length.

It is time to populate the table. We are going to start with two users only for this tutorial. Insert the following records:

ID	Username	Password
1	alex	Kulot01@
2	john	Whitewolf69

Now our table is ready. We only have two authorized login credentials which of Alex and John with their corresponding password.

Next, we will design our login form in VB6 IDE. Create a form with similar objects in it as shown below:

Form Layout

Control	Property	Value
Form	Name Caption BorderStyle Height Width	Form1 Login 1 – Fixed Single 3135 4845
Label1	Caption	User:
Label2	Caption	Password:
Text1	Name Text	txtUser
Text2	Name Text PasswordChar	txtPassword *
Command1	Name Caption	cmdCancel Cancel
Command2	Name Caption	cmdLogin Login

Controls, Properties and Values Matrix

Source Code

Form1.frm

Option Explicit

Private Sub cmdCancel_Click()   

    Unload Me

End Sub

Private Sub cmdLogin_Click()

    Dim rs As New Recordset

    Dim user As String

    Dim password As String

    Dim sql As String

   

    user = txtUser.Text

    password = txtPassword.Text

   

    sql = "SELECT * FROM Users WHERE Username = '" & user & "'"

    Debug.Print sql

    rs.Open sql, con, adOpenDynamic, adLockOptimistic

   

   

    If rs.State Then

        While Not rs.EOF

            If rs!password = password Then

                   

                'Load your main form because the access has been authorized

                Unload Me

                Exit Sub

            End If

           

            rs.MoveNext

        Wend

    End If

   

    MsgBox "Invalid Username or Password!", vbExclamation, "Authentication"

   

    rs.Close

    Set rs = Nothing

End Sub

NOTE: Upon running the application, the first form to load should be the Login form.

Test Case #1 - HINT

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.Scanner;

public class fileinput {
public static void main(String[] args) throws IOException {
BufferedReader br = null;
String sCurrentLine;
String emp[];
Scanner input=new Scanner(System.in);
String id;
boolean flag=false;
int position;
String position_desc="";
Double daily_rate=0.0;

System.out.print("Enter Code: ");
id=input.nextLine();

br = new BufferedReader(new FileReader("C:\\Users\\home\\Documents\\employees.txt"));

while ((sCurrentLine = br.readLine()) != null) {
emp=sCurrentLine.split(",");

if ( id.equals(emp[0])  ){

position=  Integer.parseInt( emp[2] );
if (position==1){
position_desc="Manager";
daily_rate=650.0;
}else if(position == 2){
position_desc="Supervisor";
daily_rate=550.0;
}else if(position == 3){
position_desc="Messenger";
daily_rate=500.0;
}

System.out.println( "Name: " + emp[1]);
System.out.println( "Position: " + position_desc);
System.out.println( "Daily Rate: " + daily_rate);

flag=true;


}

}

if (flag==false ) System.out.println("Employee not found!");


}

}