Filter GridView record with Arabic characters using C# and VB.Net in ASP.Net

kankon says:

using (SqlDataAdapter da = new SqlDataAdapter("SELECT * FROM Table_vacation WHERE namevacation = 'اجازة دورية' OR namevacation = 'اجازة دورية للاشرافيين' AND datestart >= DATEADD(MONTH, -3, GETDATE()) ORDER BY [id] DESC", con))

Add prefix N before the parameter value.

using (SqlDataAdapter da = new SqlDataAdapter("SELECT * FROM Table_vacation WHERE namevacation = N'اجازة دورية' OR namevacation = N'اجازة دورية للاشرافيين' AND datestart >= DATEADD(MONTH, -3, GETDATE()) ORDER BY [id] DESC", con))

Its better use parameterized query.

Check the below example.

HTML

<asp:GridView runat="server" ID="gvFiles" AutoGenerateColumns="false">
    <Columns>
        <asp:BoundField DataField="namevacation" HeaderText="Vacation Name" />
    </Columns>
</asp:GridView>

Namespaces

C#

using System.Configuration;
using System.Data;
using System.Data.SqlClient;

VB.Net

Imports System.Configuration
Imports System.Data
Imports System.Data.SqlClient

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        this.BindGridView();
    }
}

private void BindGridView()
{
    string str = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(str))
    {
        using (SqlCommand cmd = new SqlCommand())
        {
            cmd.CommandText = "SELECT * FROM Table_vacation WHERE namevacation = @Con1 OR namevacation = @Con2 ORDER BY [ID] DESC";
            cmd.Parameters.AddWithValue("@Con1", "اجازة دورية");
            cmd.Parameters.AddWithValue("@Con2", "اجازة دورية للاشرافيين");
            cmd.Connection = con;
            using (SqlDataAdapter da = new SqlDataAdapter(cmd))
            {
                using (DataTable dt = new DataTable())
                {
                    da.Fill(dt);
                    this.gvFiles.DataSource = dt;
                    this.gvFiles.DataBind();
                }
            }
        }
    }
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Me.BindGridView()
    End If
End Sub

Private Sub BindGridView()
    Dim str As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As SqlConnection = New SqlConnection(str)
        Using cmd As SqlCommand = New SqlCommand()
            cmd.CommandText = "SELECT * FROM Language WHERE Content = @Con1 OR Content = @Con2 ORDER BY [ID] DESC"
            cmd.Parameters.AddWithValue("@Con1", "اجازة دورية")
            cmd.Parameters.AddWithValue("@Con2", "اجازة دورية للاشرافيين")
            cmd.Connection = con
            Using da As SqlDataAdapter = New SqlDataAdapter(cmd)
                Using dt As DataTable = New DataTable()
                    da.Fill(dt)
                    Me.gvFiles.DataSource = dt
                    Me.gvFiles.DataBind()
                End Using
            End Using
        End Using
    End Using
End Sub