Hi sri.s,

I have created sample that full-fill your requirement.

SQL

CREATE TABLE [File]
(
   Id INT IDENTITY PRIMARY KEY,
   [File] VARCHAR(50)
)
GO
-------------------------------------
INSERT INTO [File] VALUES('Test.jpg')
INSERT INTO [File] VALUES('Test.pdf')
INSERT INTO [File] VALUES('Test.doc')

HTML

<div>
    <asp:GridView runat="server" ID="gvFiles" AutoGenerateColumns="false" AutoGenerateDeleteButton="true"
        AutoGenerateEditButton="true" OnRowCancelingEdit="OnRowCancelingEdit" OnRowDeleting="OnRowDeleting"
        OnRowEditing="OnRowEditing" OnRowUpdating="OnRowUpdating">
        <Columns>
            <asp:TemplateField HeaderText="ID" Visible="false">
                <ItemTemplate>
                    <asp:Label ID="lblId" Text='<%#Eval("ID") %>' runat="server" />
                </ItemTemplate>
                <EditItemTemplate>
                    <asp:Label ID="lblEditId" Text='<%#Eval("ID") %>' runat="server" />
                </EditItemTemplate>
            </asp:TemplateField>
            <asp:TemplateField HeaderText="Files">
                <ItemTemplate>
                    <asp:Label ID="lblFile" Text='<%#Eval("File") %>' runat="server" />
                </ItemTemplate>
                <EditItemTemplate>
                    <asp:FileUpload ID="fuEditFile" runat="server" />
                    <asp:RequiredFieldValidator ID="rfvEditFile" ErrorMessage="Required" ControlToValidate="fuEditFile"
                        runat="server" ForeColor="Red" Display="Dynamic" />
                    <asp:RegularExpressionValidator ID="revEditFile" ValidationExpression="([a-zA-Z0-9\s_\\.\-:])+(.doc|.jpg|.pdf)$"
                        ControlToValidate="fuEditFile" runat="server" ForeColor="Red" ErrorMessage="Please select only jpg/doc/pdf file."
                        Display="Dynamic" />
                    &nbsp;<asp:Label ID="lblEditFile" Text='<%#Eval("File") %>' runat="server" />
                </EditItemTemplate>
            </asp:TemplateField>
        </Columns>
    </asp:GridView>
</div>

Code

string str = ConfigurationManager.ConnectionStrings["conString"].ConnectionString;
protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        BindFiles();
    }
}

private void BindFiles()
{
    SqlConnection con = new SqlConnection(str);
    SqlDataAdapter da = new SqlDataAdapter("SELECT * FROM [File]", con);
    con.Open();
    DataTable dt = new DataTable();
    da.Fill(dt);
    gvFiles.DataSource = dt;
    gvFiles.DataBind();
}

protected void OnRowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
{
    gvFiles.EditIndex = -1;
    BindFiles();
}

protected void OnRowEditing(object sender, GridViewEditEventArgs e)
{
    gvFiles.EditIndex = e.NewEditIndex;
    BindFiles();
}

protected void OnRowDeleting(object sender, GridViewDeleteEventArgs e)
{
    GridViewRow row = gvFiles.Rows[e.RowIndex];
    int id = Convert.ToInt32((row.FindControl("lblId") as Label).Text);
    string fileName = (row.FindControl("lblFile") as Label).Text;
    SqlConnection con = new SqlConnection(str);
    SqlCommand cmd = new SqlCommand("DELETE FROM [File] WHERE Id = @Id", con);
    cmd.Parameters.AddWithValue("@Id", id);
    con.Open();
    cmd.ExecuteNonQuery();
    string file = Server.MapPath("~/Files/" + fileName);
    if (fileName != null || fileName != string.Empty)
    {
        if (File.Exists(file))
        {
            File.Delete(file);
        }
    }
    BindFiles();
}

protected void OnRowUpdating(object sender, GridViewUpdateEventArgs e)
{
    GridViewRow row = gvFiles.Rows[e.RowIndex];
    int id = Convert.ToInt32((row.FindControl("lblEditId") as Label).Text);
    FileUpload file = row.FindControl("fuEditFile") as FileUpload;
    string fileName = string.Empty;
    if (file.HasFile)
    {
        fileName = file.FileName;
        file.SaveAs(Server.MapPath("~/Files/") + fileName);
    }
    SqlConnection con = new SqlConnection(str);
    SqlCommand cmd = new SqlCommand("UPDATE [File] SET [File] = @File WHERE Id = @Id", con);
    cmd.Parameters.AddWithValue("@Id", id);
    cmd.Parameters.AddWithValue("@File", fileName);
    con.Open();
    cmd.ExecuteNonQuery();
    gvFiles.EditIndex = -1;
    BindFiles();
}

Screenshot