In this article I will explain with an example, how to perform CRUD i.e. Create, Read, Update, Delete operation using
Dapper library in ASP.Net using C# and VB.Net.
Installing Dapper package using Nuget
Database
I have made use of the following table Customers with the schema as follows.
![Perform CRUD using Dapper in ASP.Net]()
I have already inserted few records in the table.
![Perform CRUD using Dapper in ASP.Net]()
Note: You can download the database table SQL by clicking the download link below.
HTML Markup
The HTML Markup consists of following controls:
GridView – For displaying data.
Columns
The GridView consists of two TemplateField columns and a CommandField column.
TemplateField – The TemplateField column consists of ItemTemplate and EditItemTemplate.
ItemTemplate – It consists of a Label.
EditItemTemplate – It consists of a TextBox.
Properties
DataKeyNames – For permitting to set the names of the Column Fields, that we want to use in code but do not want to display it. Example Primary Keys, ID fields, etc.
PageSize – For permitting maximum number of rows to be displayed per page.
AllowPaging – For enabling paging in the GridView control.
EmptyDataText – For displaying text when there is no data in the GridView.
CommandField – For displaying buttons like Edit, Delete, or Select for each row in the GridView.
Events
The GridView has been assigned with the following event handlers i.e. OnRowDataBound, OnRowEditing, OnRowCancelingEdit, OnRowUpdating, OnPageIndexChanging and OnRowDeleting.
TextBox – For entering records to be added.
Button – For adding records.
The Button has been assigned with an OnClick event handler.
<asp:GridView ID="gvCustomers" runat="server" AutoGenerateColumns="false" OnRowDataBound="OnRowDataBound"
DataKeyNames="CustomerId" OnRowEditing="OnRowEditing" OnRowCancelingEdit="OnRowCancelingEdit"
PageSize="3" AllowPaging="true" OnPageIndexChanging="OnPaging" 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") %>' Width="140"></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") %>' Width="140"></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: 150px">
<asp:Button ID="btnAdd" runat="server" Text="Add" OnClick="Insert" />
</td>
</tr>
</table>
Namespaces
You will need to import the following namespaces.
C#
using Dapper;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
VB.Net
Imports Dapper
Imports System.Data
Imports System.Data.SqlClient
Imports System.Configuration
Binding the GridView using Dapper
Inside the Page Load event handler, the BindGrid method is called.
Inside the BindGrid method, first the connection is read from Web.Config file.
Then, the records are fetched from the
Customers Table of
SQL Server database using
ExecuteReader method of
Dapper library and copied to
DataTable object using
Load method.
Finally, the DataTable is assigned to the DataSource property of GridView and DataBind method is called.
C#
protected void Page_Load(object sender, EventArgs e)
{
if (!this.IsPostBack)
{
this.BindGrid();
}
}
private void BindGrid()
{
string sql = "SELECT CustomerId, Name, Country FROM Customers";
string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
using (SqlConnection con = new SqlConnection(constr))
{
using (IDataReader sdr = con.ExecuteReader(sql))
{
using (DataTable dtCustomers = new DataTable())
{
dtCustomers.Load(sdr);
gvCustomers.DataSource = dtCustomers;
gvCustomers.DataBind();
}
}
}
}
VB.Net
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
If Not Me.IsPostBack Then
Me.BindGrid()
End If
End Sub
Private Sub BindGrid()
Dim sql As String = "SELECT CustomerId, Name, Country FROM Customers"
Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
Using con As SqlConnection = New SqlConnection(constr)
Using sdr As IDataReader = con.ExecuteReader(sql)
Using dtCustomers As DataTable = New DataTable()
dtCustomers.Load(sdr)
gvCustomers.DataSource = dtCustomers
gvCustomers.DataBind()
End Using
End Using
End Using
End Sub
Inserting using Dapper in ASP.Net
When Insert button is clicked, first the connection is read from Web.Config file.
Then, using
Execute method of
Dapper library, the record is inserted into the
SQL Server database.
Finally, the GridView is populated with updated records.
C#
protected void Insert(object sender, EventArgs e)
{
string sql = "INSERT INTO Customers (Name, Country) VALUES (@Name, @Country)";
string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
using (SqlConnection con = new SqlConnection(constr))
{
string name = txtName.Text;
string country = txtCountry.Text;
con.Execute(sql, new { name, country });
}
txtName.Text = string.Empty;
txtCountry.Text = string.Empty;
this.BindGrid();
}
VB.Net
Protected Sub Insert(ByVal sender As Object, ByVal e As EventArgs)
Dim sql As String = "INSERT INTO Customers (Name, Country) VALUES (@Name, @Country)"
Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
Using con As SqlConnection = New SqlConnection(constr)
Dim name As String = txtName.Text
Dim country As String = txtCountry.Text
con.Execute(sql, New With {name, country})
End Using
txtName.Text = String.Empty
txtCountry.Text = String.Empty
Me.BindGrid()
End Sub
Edit
When the Edit Button is clicked, the GridView’s OnRowEditing event handler is triggered, where 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)
{
gvCustomers.EditIndex = e.NewEditIndex;
this.BindGrid();
}
VB.Net
Protected Sub OnRowEditing(sender As Object, e As GridViewEditEventArgs)
gvCustomers.EditIndex = e.NewEditIndex
Me.BindGrid()
End Sub
Updating using Dapper in ASP.Net
When Update button is clicked, first the connection is read from Web.Config file.
Then, using
Execute method of
Dapper library, the record is updated into the
SQL Server database.
Finally, the GridView is populated with updated records.
C#
protected void OnRowUpdating(object sender, GridViewUpdateEventArgs e)
{
GridViewRow row = gvCustomers.Rows[e.RowIndex];
int customerId = Convert.ToInt32(gvCustomers.DataKeys[e.RowIndex].Values[0]);
string name = (row.FindControl("txtName") as TextBox).Text;
string country = (row.FindControl("txtCountry") as TextBox).Text;
string sql = "UPDATE Customers SET Name=@Name, Country=@Country WHERE CustomerId=@CustomerId";
string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
using (SqlConnection con = new SqlConnection(constr))
{
con.Execute(sql, new { customerId, name, country });
}
gvCustomers.EditIndex = -1;
this.BindGrid();
}
VB.Net
Protected Sub OnRowUpdating(ByVal sender As Object, ByVal e As GridViewUpdateEventArgs)
Dim row As GridViewRow = gvCustomers.Rows(e.RowIndex)
Dim customerId As Integer = Convert.ToInt32(gvCustomers.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 sql As String = "UPDATE Customers SET Name=@Name, Country=@Country WHERE CustomerId=@CustomerId"
Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
Using con As SqlConnection = New SqlConnection(constr)
con.Execute(sql, New With {customerId, name, country})
End Using
gvCustomers.EditIndex = -1
Me.BindGrid()
End Sub
Cancel Edit
When the Cancel Button is clicked, the GridView’s OnRowCancelingEdit event handler is triggered and the EditIndex is set to -1 and the GridView is populated with data using the BindGrid method.
C#
protected void OnRowCancelingEdit(object sender, EventArgs e)
{
gvCustomers.EditIndex = -1;
this.BindGrid();
}
VB.Net
Protected Sub OnRowCancelingEdit(sender As Object, e As EventArgs)
gvCustomers.EditIndex = -1
Me.BindGrid()
End Sub
Deleting using Dapper in ASP.Net
When Delete button is clicked, first the connection is read from Web.Config file.
Then, using
Execute method of
Dapper library, the record is deleted from the
SQL Server database.
Finally, BindGrid method is called.
C#
protected void OnRowDeleting(object sender, GridViewDeleteEventArgs e)
{
int customerId = Convert.ToInt32(gvCustomers.DataKeys[e.RowIndex].Values[0]);
string sql = "DELETE FROM Customers WHERE CustomerId = @CustomerId";
string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
using (SqlConnection con = new SqlConnection(constr))
{
con.Execute(sql, new { customerId });
}
this.BindGrid();
}
VB.Net
Protected Sub OnRowDeleting(ByVal sender As Object, ByVal e As GridViewDeleteEventArgs)
Dim customerId As Integer = Convert.ToInt32(gvCustomers.DataKeys(e.RowIndex).Values(0))
Dim sql As String = "DELETE FROM Customers WHERE CustomerId = @CustomerId"
Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
Using con As SqlConnection = New SqlConnection(constr)
con.Execute(sql, New With {customerId})
End Using
Me.BindGrid()
End Sub
Delete Confirmation Message
The delete operation will be confirmed using
JavaScript Confirmation Box, thus inside the
OnRowDataBound event handler, the
Delete LinkButton is assigned with a
JavaScript onclick event handler.
C#
protected void OnRowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow && e.Row.RowIndex != gvCustomers.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 <> gvCustomers.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
Paging
Inside the OnPageIndexChanging event handler, the PageIndex property of the GridView is updated with the new Page Number which was clicked.
Finally, the GridView is populated using the BindGrid method which in-turn displays the new GridView page.
C#
protected void OnPaging(object sender, GridViewPageEventArgs e)
{
gvCustomers.PageIndex = e.NewPageIndex;
this.BindGrid();
}
VB.Net
Protected Sub OnPaging(ByVal sender As Object, ByVal e As GridViewPageEventArgs)
gvCustomers.PageIndex = e.NewPageIndex
Me.BindGrid()
End Sub
Screenshot
![Perform CRUD using Dapper in ASP.Net]()
Downloads
