In this article I will explain a tutorial with example, how to use Web API with database in ASP.Net MVC Razor.
This article will illustrate how to create Action methods in Web API for performing the CRUD operations with database using Entity Framework in ASP.Net MVC Razor.
Note: For beginners in ASP.Net MVC and Web API, please refer my article: What is Web API, why to use it and how to use it in ASP.Net MVC for details about using and configuring Web API.
 
 
Database
I have made use of the following table Customers with the schema as follows. CustomerId is an Auto-Increment (Identity) column.
Using Web API with Database Tutorial with example in ASP.Net MVC
 
I have already inserted few records in the table.
Using Web API with Database Tutorial with example in ASP.Net MVC
 
Note: You can download the database table SQL by clicking the download link below.
          Download SQL file
 
 
Entity Framework Model
Once the Entity Framework is configured and connected to the database table, the Model will look as shown below.
Note: For beginners in ASP.Net MVC and Entity Framework, please refer my article ASP.Net MVC: Simple Entity Framework Tutorial with example. It covers all the information needed for connecting and configuring Entity Framework.
 
Using Web API with Database Tutorial with example in ASP.Net MVC
 
 
Controller
The Controller consists of the following Action method.
Action method for handling GET operation
Inside this Action method, all the records from the Customers table is returned to the View as a Generic List collection.
public class HomeController : Controller
{
    // GET: Home
    public ActionResult Index()
    {
        CustomersEntities entities = new CustomersEntities();
        return View(entities.Customers);
    }
}
 
 
Web API Controller
The Web API Controller consists of the following three Action methods.
Action method for Inserting
Inside this Action method, the received Customer object is inserted into the Customers table and the updated Customer object with generated Customer Id is returned back to the calling jQuery AJAX function.
 
Action method for Updating
Inside this Action method, the Customer object is received as parameter. The CustomerId value of the received Customer object is used to reference the Customer record in the Customer Entities.
Once the record is referenced, the values of Name and Country are updated and the changes are updated into the Customer table.
 
Action method for Deleting
Inside this Action method, the CustomerId value is received as parameter. The CustomerId value is used to reference the Customer record in the Customer Entities.
Once the record is referenced, the Customer record is deleted from the Customers table.
public class AjaxAPIController : ApiController
{
    [Route("api/AjaxAPI/InsertCustomer")]
    [HttpPost]
    public Customer InsertCustomer(Customer _customer)
    {
        using (CustomersEntities entities = new CustomersEntities())
        {
            entities.Customers.Add(_customer);
            entities.SaveChanges();
        }
 
        return _customer;
    }
 
    [Route("api/AjaxAPI/UpdateCustomer")]
    [HttpPost]
    public bool UpdateCustomer(Customer _customer)
    {
        using (CustomersEntities entities = new CustomersEntities())
        {
            Customer updatedCustomer = (from c in entities.Customers
                                        where c.CustomerId == _customer.CustomerId
                                        select c).FirstOrDefault();
            updatedCustomer.Name = _customer.Name;
            updatedCustomer.Country = _customer.Country;
            entities.SaveChanges();
        }
 
        return true;
    }
 
    [Route("api/AjaxAPI/DeleteCustomer")]
    [HttpPost]
    public void DeleteCustomer(Customer _customer)
    {
        using (CustomersEntities entities = new CustomersEntities())
        {
            Customer customer = (from c in entities.Customers
                                 where c.CustomerId == _customer.CustomerId
                                 select c).FirstOrDefault();
            entities.Customers.Remove(customer);
            entities.SaveChanges();
        }
    }
}
 
 
View
Inside the View, in the very first line the Entity Framework Customer Model class is declared as Model for the View.
Display
For displaying the records, an HTML Table is used. A loop will be executed over the Model which will generate the HTML Table rows with the Customer records.
 
Insert
When the Add button is clicked the name and the country values are fetched from their respective TextBoxes and then passed to the InsertCustomer Action method using jQuery AJAX call.
Once the response is received, a new row is appended to the HTML table using the AppendRow function.
 
Edit
When the Edit Button is clicked, the reference of the HTML Table row is determined and the HTML SPAN elements are made hidden while the TextBoxes are made visible in the Name and Country columns of the HTML Table.
 
Update
When the Update Button is clicked, the reference of the HTML Table row is determined and the updated values are fetched from the respective TextBoxes of Name and Country columns while the CustomerId is determined from the HTML SPAN element of the CustomerId column.
The values of CustomerId, Name and Country are passed to the UpdateCustomer Action method using jQuery AJAX call.
Once the response is received, the HTML SPAN elements are made visible and the TextBoxes are made hidden for the Name and Country columns of the HTML Table row.
 
Cancel
When the Cancel Button is clicked, the reference of the HTML Table row is determined and the HTML SPAN elements are made visible while the TextBoxes are made hidden in the Name and Country columns of the HTML Table row.
 
Delete
When the Delete Button is clicked, the reference of the HTML Table row is determined and the value of the CustomerId is fetched and passed to the DeleteCustomer Action method using jQuery AJAX call.
Once the response is received the respective row is removed from the HTML Table row.
@model IEnumerable<jQuery_AJAX_WebAPI_CRUD_MVC.Customer>
@{
    Layout = null;
}
 
<!DOCTYPE html>
 
<html>
<head>
    <meta name="viewport" content="width=device-width"/>
    <title>Index</title>
</head>
<body>
    <table id="tblCustomers" class="table" cellpadding="0" cellspacing="0">
        <tr>
            <th style="width:100px">Customer Id</th>
            <th style="width:150px">Name</th>
            <th style="width:150px">Country</th>
            <th></th>
        </tr>
        <tr>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
        </tr>
        @foreach (Customer customer in Model)
        {
            <tr>
                <td class="CustomerId">
                    <span>@customer.CustomerId</span>
                </td>
                <td class="Name">
                    <span>@customer.Name</span>
                    <input type="text" value="@customer.Name" style="display:none"/>
                </td>
                <td class="Country">
                    <span>@customer.Country</span>
                    <input type="text" value="@customer.Country" style="display:none"/>
                </td>
                <td>
                    <a class="Edit" href="javascript:;">Edit</a>
                    <a class="Update" href="javascript:;" style="display:none">Update</a>
                    <a class="Cancel" href="javascript:;" style="display:none">Cancel</a>
                    <a class="Delete" href="javascript:;">Delete</a>
                </td>
            </tr>
        }
    </table>
    <table border="0" cellpadding="0" cellspacing="0">
        <tr>
            <td style="width: 150px">
                Name<br/>
                <input type="text" id="txtName" style="width:140px"/>
            </td>
            <td style="width: 150px">
                Country:<br/>
                <input type="text" id="txtCountry" style="width:140px"/>
            </td>
            <td style="width: 200px">
                <br/>
                <input type="button" id="btnAdd" value="Add"/>
            </td>
        </tr>
    </table>
 
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
    <script type="text/javascript" src="http://ajax.cdnjs.com/ajax/libs/json2/20110223/json2.js"></script>
    <script type="text/javascript">
        $(function () {
            //Remove the dummy row if data present.
            if ($("#tblCustomers tr").length > 2) {
                $("#tblCustomers tr:eq(1)").remove();
            }
        });
        function AppendRow(row, customerId, name, country) {
            //Bind CustomerId.
            $(".CustomerId", row).find("span").html(customerId);
 
            //Bind Name.
            $(".Name", row).find("span").html(name);
            $(".Name", row).find("input").val(name);
 
            //Bind Country.
            $(".Country", row).find("span").html(country);
            $(".Country", row).find("input").val(country);
            $("#tblCustomers").append(row);
        };
 
        //Add event handler.
        $("body").on("click", "#btnAdd", function () {
            var txtName = $("#txtName");
            var txtCountry = $("#txtCountry");
            var _customer = {};
            _customer.Name = txtName.val();
            _customer.Country = txtCountry.val();
            $.ajax({
                type: "POST",
                url: "/api/AjaxAPI/InsertCustomer",
                data: JSON.stringify(_customer),
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                success: function (r) {
                    var row = $("#tblCustomers tr:last-child").clone(true);
                    AppendRow(row, r.CustomerId, r.Name, r.Country);
                    txtName.val("");
                    txtCountry.val("");
                }
            });
        });
 
        //Edit event handler.
        $("body").on("click", "#tblCustomers .Edit", function () {
            var row = $(this).closest("tr");
            $("td", row).each(function () {
                if ($(this).find("input").length > 0) {
                    $(this).find("input").show();
                    $(this).find("span").hide();
                }
            });
            row.find(".Update").show();
            row.find(".Cancel").show();
            row.find(".Delete").hide();
            $(this).hide();
        });
 
        //Update event handler.
        $("body").on("click", "#tblCustomers .Update", function () {
            var row = $(this).closest("tr");
            $("td", row).each(function () {
                if ($(this).find("input").length > 0) {
                    var span = $(this).find("span");
                    var input = $(this).find("input");
                    span.html(input.val());
                    span.show();
                    input.hide();
                }
            });
            row.find(".Edit").show();
            row.find(".Delete").show();
            row.find(".Cancel").hide();
            $(this).hide();
            var _customer = {};
            _customer.CustomerId = row.find(".CustomerId").find("span").html();
            _customer.Name = row.find(".Name").find("span").html();
            _customer.Country = row.find(".Country").find("span").html();
            $.ajax({
                type: "POST",
                url: "/api/AjaxAPI/UpdateCustomer",
                data: JSON.stringify(_customer),
                contentType: "application/json; charset=utf-8",
                dataType: "json"
            });
        });
 
        //Cancel event handler.
        $("body").on("click", "#tblCustomers .Cancel", function () {
            var row = $(this).closest("tr");
            $("td", row).each(function () {
                if ($(this).find("input").length > 0) {
                    var span = $(this).find("span");
                    var input = $(this).find("input");
                    input.val(span.html());
                    span.show();
                    input.hide();
                }
            });
            row.find(".Edit").show();
            row.find(".Delete").show();
            row.find(".Update").hide();
            $(this).hide();
        });
 
        //Delete event handler.
        $("body").on("click", "#tblCustomers .Delete", function () {
            if (confirm("Do you want to delete this row?")) {
                var row = $(this).closest("tr");
                var _customer = {};
                _customer.CustomerId = row.find("span").html();
                $.ajax({
                    type: "POST",
                    url: "/api/AjaxAPI/DeleteCustomer",
                    data: JSON.stringify(_customer),
                    contentType: "application/json; charset=utf-8",
                    dataType: "json",
                    success: function (response) {
                        row.remove();
                    }
                });
            }
        });
    </script>
</body>
</html>
 
 
Screenshot
Using Web API with Database Tutorial with example in ASP.Net MVC
 
 
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