The CustomerID field from the Customers controller should have all values formatted in uppercase.

Let’s create a business rule in C# or Visual Basic to convert all user input to uppercase.

Start the Project Designer. In the Project Explorer, switch to the Controllers tab and double-click on Customers controller node.

Change the Handler property:

Property	New Value
Handler	CustomersRule

Press OK to save the controller. In the Project Explorer, double-click on Customers / Fields / CustomerID field node.

Make the following changes:

Property	New Value
The value of this field is calculated by a business rule expression.	True
Context Fields	CustomerID

Exit the designer and generate the application.

Click on the project name, and press Design. Visual Studio will open the project.

In the Solution Explorer, double-click on ~\App_Code\Rules\CustomersRule.cs(vb) file.

Replace the sample code base with the following:

C#:

using System;
using System.Data;
using System.Collections.Generic;
using System.Linq;
using MyCompany.Data;

namespace MyCompany.Rules
{
    public partial class CustomersRule : MyCompany.Data.BusinessRules
    {
        [ControllerAction("Customers", "Insert", ActionPhase.Before)]
        [ControllerAction("Customers", "Update", ActionPhase.Before)]
        [ControllerAction("Customers", "Calculate", ActionPhase.Execute)]
        public void CalculateCustomerID(string customerID)
        {
            UpdateFieldValue("CustomerID", customerID.ToUpper());
        }
    }
}

Visual Basic:

Imports MyCompany.Data
Imports System
Imports System.Collections.Generic
Imports System.Data
Imports System.Linq
Namespace MyCompany.Rules
    Partial Public Class CustomersRule
        Inherits MyCompany.Data.BusinessRules
        <ControllerAction("Customers", "Insert", ActionPhase.Before)>
        <ControllerAction("Customers", "Update", ActionPhase.Before)>
        <ControllerAction("Customers", "Calculate", ActionPhase.Execute)>
        Public Sub CalculateCustomerID(ByVal customerID As String)
            UpdateFieldValue("CustomerID", customerID.ToUpper())
        End Sub
    End Class
End Namespace

Save the file, and switch to the web application. Navigate to the Customers page, and create a new record. Type in lowercase letters for Customer# field.

Press Tab or click on another area of the page. The text in Customer# will be converted to uppercase.

The same business logic can be implemented with the help of SQL Business Rules.