In this article I will explain how to build a simple user registration form that will allow user register to the website in ASP.Net using C# and VB.Net.
User will fill up the registration form with details such as username, password, email address, etc. and these details will be saved in the database table.
The registration form will also make sure that duplicate username and email addresses are not saved by verifying whether username and email address must not exist in the table.
 
 

Database

For this article I have created a new database named LoginDB which contains the following table named Users in it.
Simple User Registration Form Example in ASP.Net
 
 

HTML Markup

The following HTML Markup consists of:
TextBox – For capturing the details of the User.
RequiredFieldValidator – For validating the details entered by the User.
CompareValidator – For comparing the Passwords of the User.
RegularExpressionValidator – For validating the Email Address of the User.
Button – For submitting the registration.
The Button has been assigned with an OnClick event handler.
<table border="0" cellpadding="0" cellspacing="0">
    <tr>
        <th colspan="3">Registration</th>
    </tr>
    <tr>
        <td>Username</td>
        <td> <asp:TextBox ID="txtUsername" runat="server" /></td>
        <td>
            <asp:RequiredFieldValidator ErrorMessage="Required" ForeColor="Red" ControlToValidate="txtUsername"
                runat="server" />
        </td>
    </tr>
    <tr>
        <td>Password</td>
        <td><asp:TextBox ID="txtPassword" runat="server" TextMode="Password" /></td>
        <td>
            <asp:RequiredFieldValidator ErrorMessage="Required" ForeColor="Red" ControlToValidate="txtPassword"
                runat="server" />
        </td>
    </tr>
    <tr>
        <td>Confirm Password</td>
        <td><asp:TextBox ID="txtConfirmPassword" runat="server" TextMode="Password" /></td>
        <td>
            <asp:CompareValidator ErrorMessage="Passwords do not match." ForeColor="Red" ControlToCompare="txtPassword"
                ControlToValidate="txtConfirmPassword" runat="server" />
        </td>
    </tr>
    <tr>
        <td>Email</td>
        <td> <asp:TextBox ID="txtEmail" runat="server" /></td>
        <td>
            <asp:RequiredFieldValidator ErrorMessage="Required" Display="Dynamic" ForeColor="Red"
                ControlToValidate="txtEmail" runat="server" />
            <asp:RegularExpressionValidator runat="server" Display="Dynamic" ValidationExpression="\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*"
                ControlToValidate="txtEmail" ForeColor="Red" ErrorMessage="Invalid email address." />
        </td>
    </tr>
    <tr>
        <td></td>
        <td><asp:Button Text="Submit" runat="server" OnClick="RegisterUser" /> </td>
        <td></td>
    </tr>
</table>
 
 

Stored Procedure to insert the User details

The following stored procedure is used to insert the user details such as username, password and email address.
The stored procedure first checks whether the username supplied already exists, if yes then it will return negative 1 value.
Then the stored procedure checks whether the email address supplied already exists, if yes then it will return negative 2 value.
If both username and email address are valid then the record will be inserted and the auto-generated UserId will be returned by the stored procedure.
CREATE PROCEDURE [dbo].[Insert_User]
    @Username NVARCHAR(20),
    @Password NVARCHAR(20),
    @Email NVARCHAR(30)
AS
BEGIN
    SET NOCOUNT ON;
    IF EXISTS(SELECT UserId FROM Users WHERE Username = @Username)
    BEGIN
        SELECT -1 -- Username exists.
    END
    ELSE IF EXISTS(SELECT UserId FROM Users WHERE Email = @Email)
    BEGIN
        SELECT -2 -- Email exists.
    END
    ELSE
    BEGIN
        INSERT INTO [Users]
             ([Username]
             ,[Password]
             ,[Email]
             ,[CreatedDate])
        VALUES
            (@Username
            ,@Password
            ,@Email
            ,GETDATE())
        SELECT SCOPE_IDENTITY() -- UserId   
    END
END
 
 

Namespaces

You will need to import the following namespace.
C#
using System.Data;
using System.Configuration;
using System.Data.SqlClient;
 
VB.Net
Imports System.Data
Imports System.Configuration
Imports System.Data.SqlClient
 
 

Inserting the User Details

When the Register Button is clicked, the values from the Registration Form’s TextBoxes are captured and passed to the Stored Procedure.
The value returned from the Stored Procedure is captured in a variable and then based on its value appropriate message is displayed using JavaScript Alert message box.
C#
protected void RegisterUser(object sender, EventArgs e)
{
    int userId = 0;
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand("Insert_User"))
        {
            using (SqlDataAdapter sda = new SqlDataAdapter())
            {
                cmd.CommandType = CommandType.StoredProcedure;
                cmd.Parameters.AddWithValue("@Username", txtUsername.Text.Trim());
                cmd.Parameters.AddWithValue("@Password", txtPassword.Text.Trim());
                cmd.Parameters.AddWithValue("@Email", txtEmail.Text.Trim());
                cmd.Connection = con;
                con.Open();
                userId = Convert.ToInt32(cmd.ExecuteScalar());
                con.Close();
            }
        }
        string message = string.Empty;
        switch (userId)
        {
            case -1:
                message = "Username already exists.\\nPlease choose a different username.";
                break;
            case -2:
                message = "Supplied email address has already been used.";
                break;
            default:
                message = "Registration successful.\\nUser Id: " + userId.ToString();
                break;
        }
        ClientScript.RegisterStartupScript(GetType(), "alert", "alert('" + message + "');", true);
    }
}
 
VB.Net
Protected Sub RegisterUser(sender As Object, e As EventArgs)
    Dim userId As Integer = 0
    Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As New SqlConnection(constr)
        Using cmd As New SqlCommand("Insert_User")
            Using sda As New SqlDataAdapter()
                cmd.CommandType = CommandType.StoredProcedure
                cmd.Parameters.AddWithValue("@Username", txtUsername.Text.Trim())
                cmd.Parameters.AddWithValue("@Password", txtPassword.Text.Trim())
                cmd.Parameters.AddWithValue("@Email", txtEmail.Text.Trim())
                cmd.Connection = con
                con.Open()
                userId = Convert.ToInt32(cmd.ExecuteScalar())
                con.Close()
            End Using
        End Using
        Dim message As String = String.Empty
        Select Case userId
            Case -1
                message = "Username already exists.\nPlease choose a different username."
                Exit Select
            Case -2
                message = "Supplied email address has already been used."
                Exit Select
            Case Else
                message = "Registration successful.\nUser Id: " + userId.ToString()
                Exit Select
        End Select
        ClientScript.RegisterStartupScript(GetType(), "alert", (Convert.ToString("alert('") & message) & "');", True)
    End Using
End Sub
 
 

Screenshots

Entering details

Simple User Registration Form Example in ASP.Net
 

When validation fails

Simple User Registration Form Example in ASP.Net
 

Message Box when registration is successful

Simple User Registration Form Example in ASP.Net
 

Message Box when username already exists

Simple User Registration Form Example in ASP.Net
 

Message Box when email address already exists

Simple User Registration Form Example in ASP.Net
 

User record inserted in table

Simple User Registration Form Example in ASP.Net
 
 

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