In this article I will explain how to perform Select, Insert, Edit, Update and Delete operations using a Web Service and Web Method in ASP.Net.
In order to illustrate, I’ll be using a GridView in which I will perform Insert, Edit, Update and Delete operations using a Web Service in ASP.Net, C# and VB.Net.
 
Database
I have made use of the following table Customers with the schema as follows.
Select Insert Edit Update Delete using Web Service in ASP.Net
 
I have already inserted few records in the table.
Select Insert Edit Update Delete using Web Service in ASP.Net
 
Note: You can download the database table SQL by clicking the download link below.
         Download SQL file
 
 
Building the Web Service
1. First step is to add a Web Service.
Select Insert Edit Update Delete using Web Service in ASP.Net
 
2. Once the Web Service is added. You will need to add the following namespaces.
C#
using System.Data;
using System.Configuration;
using System.Data.SqlClient;
 
VB.Net
Imports System.Data
Imports System.Configuration
Imports System.Data.SqlClient
 
3. Third step is to add the WebMethods to perform Select, Insert, Edit, Update and Delete operations.
C#
[WebMethod]
public DataTable Get()
{
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand("SELECT * FROM Customers"))
        {
            using (SqlDataAdapter sda = new SqlDataAdapter())
            {
                cmd.Connection = con;
                sda.SelectCommand = cmd;
                using (DataTable dt = new DataTable())
                {
                    dt.TableName = "Customers";
                    sda.Fill(dt);
                    return dt;
                }
            }
        }
    }
}
 
[WebMethod]
public void Insert(string name, string country)
{
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand("INSERT INTO Customers (Name, Country) VALUES (@Name, @Country)"))
        {
            cmd.Parameters.AddWithValue("@Name", name);
            cmd.Parameters.AddWithValue("@Country", country);
            cmd.Connection = con;
            con.Open();
            cmd.ExecuteNonQuery();
            con.Close();
        }
    }
}
 
[WebMethod]
public void Update(int customerId, string name, string country)
{
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand("UPDATE Customers SET Name = @Name, Country = @Country WHERE CustomerId = @CustomerId"))
        {
            cmd.Parameters.AddWithValue("@CustomerId", customerId);
            cmd.Parameters.AddWithValue("@Name", name);
            cmd.Parameters.AddWithValue("@Country", country);
            cmd.Connection = con;
            con.Open();
            cmd.ExecuteNonQuery();
            con.Close();
        }
    }
}
 
[WebMethod]
public void Delete(int customerId)
{
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand("DELETE FROM Customers WHERE CustomerId = @CustomerId"))
        {
            cmd.Parameters.AddWithValue("@CustomerId", customerId);
            cmd.Connection = con;
            con.Open();
            cmd.ExecuteNonQuery();
            con.Close();
        }
    }
}
 
VB.Net
<WebMethod()> _
Public Function [Get]() As DataTable
    Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As New SqlConnection(constr)
        Using cmd As New SqlCommand("SELECT * FROM Customers")
            Using sda As New SqlDataAdapter()
                cmd.Connection = con
                sda.SelectCommand = cmd
                Using dt As New DataTable()
                    dt.TableName = "Customers"
                    sda.Fill(dt)
                    Return dt
                End Using
            End Using
        End Using
    End Using
End Function
 
<WebMethod()> _
Public Sub Insert(name As String, country As String)
    Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As New SqlConnection(constr)
        Using cmd As New SqlCommand("INSERT INTO Customers (Name, Country) VALUES (@Name, @Country)")
            cmd.Parameters.AddWithValue("@Name", name)
            cmd.Parameters.AddWithValue("@Country", country)
            cmd.Connection = con
            con.Open()
            cmd.ExecuteNonQuery()
            con.Close()
        End Using
    End Using
End Sub
 
<WebMethod()> _
Public Sub Update(customerId As Integer, name As String, country As String)
    Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As New SqlConnection(constr)
        Using cmd As New SqlCommand("UPDATE Customers SET Name = @Name, Country = @Country WHERE CustomerId = @CustomerId")
            cmd.Parameters.AddWithValue("@CustomerId", customerId)
            cmd.Parameters.AddWithValue("@Name", name)
            cmd.Parameters.AddWithValue("@Country", country)
            cmd.Connection = con
            con.Open()
            cmd.ExecuteNonQuery()
            con.Close()
        End Using
    End Using
End Sub
 
<WebMethod()> _
Public Sub Delete(customerId As Integer)
    Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As New SqlConnection(constr)
        Using cmd As New SqlCommand("DELETE FROM Customers WHERE CustomerId = @CustomerId")
            cmd.Parameters.AddWithValue("@CustomerId", customerId)
            cmd.Connection = con
            con.Open()
            cmd.ExecuteNonQuery()
            con.Close()
        End Using
    End Using
End Sub
 
4. Finally you will need to add the Web Reference of the Web Service we just created to the project as shown below.
Note: For more details on adding Web Reference of a Web Service, please refer my article, How to add reference of Web Service (ASMX) in ASP.Net using Visual Studio
 
Select Insert Edit Update Delete using Web Service in ASP.Net
 
 
HTML Markup
The HTML Markup consists of an ASP.Net GridView with multiple event handlers assigned which will be discussed later.
The GridView has a CommandField column which will display the command buttons i.e. Edit, Update, Cancel and Delete.
Below the GridView there’s a Form which will allow us to insert data to the SQL Server database table using the Web Service.
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" DataKeyNames="CustomerId"
OnRowDataBound="OnRowDataBound" OnRowEditing="OnRowEditing" OnRowCancelingEdit="OnRowCancelingEdit"
OnRowUpdating="OnRowUpdating" OnRowDeleting="OnRowDeleting" EmptyDataText="No records has been added.">
<Columns>
    <asp:TemplateField HeaderText="Name" ItemStyle-Width="150">
        <ItemTemplate>
            <asp:Label ID="lblName" runat="server" Text='<%# Eval("Name") %>'></asp:Label>
        </ItemTemplate>
        <EditItemTemplate>
            <asp:TextBox ID="txtName" runat="server" Text='<%# Eval("Name") %>'></asp:TextBox>
        </EditItemTemplate>
    </asp:TemplateField>
    <asp:TemplateField HeaderText="Country" ItemStyle-Width="150">
        <ItemTemplate>
            <asp:Label ID="lblCountry" runat="server" Text='<%# Eval("Country") %>'></asp:Label>
        </ItemTemplate>
        <EditItemTemplate>
            <asp:TextBox ID="txtCountry" runat="server" Text='<%# Eval("Country") %>'></asp:TextBox>
        </EditItemTemplate>
    </asp:TemplateField>
    <asp:CommandField ButtonType="Link" ShowEditButton="true" ShowDeleteButton="true" ItemStyle-Width="150"/>
</Columns>
</asp:GridView>
<table border="1" cellpadding="0" cellspacing="0" style="border-collapse: collapse">
<tr>
    <td style="width: 150px">
        Name:<br />
        <asp:TextBox ID="txtName" runat="server" Width="140" />
    </td>
    <td style="width: 150px">
        Country:<br />
        <asp:TextBox ID="txtCountry" runat="server" Width="140" />
    </td>
    <td style="width: 100px">
        <asp:Button ID="btnAdd" runat="server" Text="Add" OnClick="Insert" />
    </td>
</tr>
</table>
 
 
Binding the GridView using Web Service
The GridView is populated from the database inside the Page Load event of the page.
C#
protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        this.BindGrid();
    }
}
 
private void BindGrid()
{
    CRUD_Service.ServiceCS service = new CRUD_Service.ServiceCS();
    GridView1.DataSource = service.Get();
    GridView1.DataBind();
}
 
VB.Net
Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Me.BindGrid()
    End If
End Sub
 
Private Sub BindGrid()
    Dim service As New CRUD_ServiceVB.ServiceVB()
    GridView1.DataSource = service.[Get]()
    GridView1.DataBind()
End Sub
 
Following is the GridView containing records.
Select Insert Edit Update Delete using Web Service in ASP.Net
 
For the GridView I have set EmptyDataText to display message when no records are present.
Select Insert Edit Update Delete using Web Service in ASP.Net
 
 
Inserting records using Web Service
The following event handler is executed when the Add Button is clicked. The name and the country values are fetched from their respective TextBoxes and then passed to the Web Service.
Finally the GridView is again populated with data by making call to the BindGrid method.
C#
protected void Insert(object sender, EventArgs e)
{
    CRUD_Service.ServiceCS service = new CRUD_Service.ServiceCS();
    service.Insert(txtName.Text.Trim(), txtCountry.Text.Trim());
    this.BindGrid();
}
 
VB.Net
Protected Sub Insert(sender As Object, e As EventArgs)
    Dim service As New CRUD_ServiceVB.ServiceVB()
    service.Insert(txtName.Text.Trim(), txtCountry.Text.Trim())
    Me.BindGrid()
End Sub
 
 
Editing and Updating using Web Service
Edit
When the Edit Button is clicked, the GridView’s OnRowEditing event handler is triggered. Here simply the EditIndex of the GridView is updated with the Row Index of the GridView Row to be edited.
C#
protected void OnRowEditing(object sender, GridViewEditEventArgs e)
{
    GridView1.EditIndex = e.NewEditIndex;
    this.BindGrid();
}
 
VB.Net
Protected Sub OnRowEditing(sender As Object, e As GridViewEditEventArgs)
    GridView1.EditIndex = e.NewEditIndex
    Me.BindGrid()
End Sub
 
Update
When the Update Button is clicked, the GridView’s OnRowUpdating event handler is triggered.
CustomerId which is the primary key is fetched from the DataKey property of GridView while the Name and Country fields are fetched from their respective TextBoxes and are passed to the Web Service.
For more details on DataKeys please refer my article DataKeyNames in GridView example in ASP.Net.
 
C#
protected void OnRowUpdating(object sender, GridViewUpdateEventArgs e)
{
    GridViewRow row = GridView1.Rows[e.RowIndex];
    int customerId = Convert.ToInt32(GridView1.DataKeys[e.RowIndex].Values[0]);
    string name = (row.FindControl("txtName") as TextBox).Text;
    string country = (row.FindControl("txtCountry") as TextBox).Text;
    CRUD_Service.ServiceCS service = new CRUD_Service.ServiceCS();
    service.Update(customerId, name, country);
    GridView1.EditIndex = -1;
    this.BindGrid();
}
 
VB.Net
Protected Sub OnRowUpdating(sender As Object, e As GridViewUpdateEventArgs)
    Dim row As GridViewRow = GridView1.Rows(e.RowIndex)
    Dim customerId As Integer = Convert.ToInt32(GridView1.DataKeys(e.RowIndex).Values(0))
    Dim name As String = TryCast(row.FindControl("txtName"), TextBox).Text
    Dim country As String = TryCast(row.FindControl("txtCountry"), TextBox).Text
    Dim service As New CRUD_ServiceVB.ServiceVB()
    service.Update(customerId, name, country)
    GridView1.EditIndex = -1
    Me.BindGrid()
End Sub
 
Cancel Edit
When the Cancel Button is clicked, the GridView’s OnRowCancelingEdit event handler is triggered. Here the EditIndex is set to -1 and the GridView is populated with data.
C#
protected void OnRowCancelingEdit(object sender, EventArgs e)
{
    GridView1.EditIndex = -1;
    this.BindGrid();
}
 
VB.Net
Protected Sub OnRowCancelingEdit(sender As Object, e As EventArgs)
    GridView1.EditIndex = -1
    Me.BindGrid()
End Sub
 
Select Insert Edit Update Delete using Web Service in ASP.Net
 
 
Deleting records using Web Service
When the Delete Button is clicked, the GridView’s OnRowDeleting event handler is triggered.
CustomerId which is the primary key is fetched from the DataKey property of GridView and is passed to the Web Service in order to delete the record.
C#
protected void OnRowDeleting(object sender, GridViewDeleteEventArgs e)
{
    int customerId = Convert.ToInt32(GridView1.DataKeys[e.RowIndex].Values[0]);
    CRUD_Service.ServiceCS service = new CRUD_Service.ServiceCS();
    service.Delete(customerId);
    this.BindGrid();
}
 
VB.Net
Protected Sub OnRowDeleting(sender As Object, e As GridViewDeleteEventArgs)
    Dim customerId As Integer = Convert.ToInt32(GridView1.DataKeys(e.RowIndex).Values(0))
    Dim service As New CRUD_ServiceVB.ServiceVB()
    service.Delete(customerId)
    Me.BindGrid()
End Sub
 
In order to display a confirmation message when deleting row, I have made use of OnRowDataBound event handler where I have first determined the Delete Button and then I have attach the JavaScript Confirm to its client side Click event handler.
C#
protected void OnRowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow && e.Row.RowIndex != GridView1.EditIndex)
    {
        (e.Row.Cells[2].Controls[2] as LinkButton).Attributes["onclick"] = "return confirm('Do you want to delete this row?');";
    }
}
 
VB.Net
Protected Sub OnRowDataBound(sender As Object, e As GridViewRowEventArgs)
    If e.Row.RowType = DataControlRowType.DataRow AndAlso e.Row.RowIndex <> GridView1.EditIndex Then
        TryCast(e.Row.Cells(2).Controls(2), LinkButton).Attributes("onclick") = "return confirm('Do you want to delete this row?');"
    End If
End Sub
 
Select Insert Edit Update Delete using Web Service in ASP.Net
 
 
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