How to get text box value in Page_init method in asp.net?

Question

Here is my situation. I want to perform paging, grouping and filtering. So that I am using page_init method. As per my code it's working fine. But user only can give where clause conditions like

For example, I have a textbox in my page. that textbox ID="txtQuery", in that textbox user will enter the where clause like itemID='45366' So i have to make my code like below

cmd.commandText="select * from TABLE_NAME where "+txtQuery.text

So this will show the records. This is the problem now. When I make cmd.commandText like above it throws an error

System.Data.SqlClient.SqlException: Incorrect syntax near 'where'.

If i give directly, It's working fine without any error.

This is my code

string whereQuery = "";
protected void Page_Init(object sender, EventArgs e)
{
    // initialize SomeDataTable
    if (IsPostBack)
    {
        string cs = ConfigurationManager.ConnectionStrings["HQMatajerConnectionString"].ConnectionString;
        whereQuery = getWhereQuery();
        //Response.Write("<br/><br/><br/><br/>" + whereQuery);
        using (SqlConnection con = new SqlConnection(cs))
        {
            string query = @"select transactions.storeid as StoreID, YEAR(transactions.Time) Year, MONTH(transactions.Time) Month, 
                        transactionsEntry.TransactionNumber,transactionsEntry.Quantity,
                        items.ItemLookupCode,items.DepartmentID,items.CategoryID,items.SubDescription1,
                        suppliers.SupplierName,suppliers.Code
                        FROM        [HQMatajer].[dbo].[Transaction] as transactions
                        RIGHT JOIN  [HQMatajer].[dbo].[TransactionEntry] as transactionsEntry
                        ON transactions.TransactionNumber=transactionsEntry.TransactionNumber 
                        INNER JOIN  [HQMatajer].[dbo].[Item] as items
                        ON transactionsEntry.ItemID=items.ID
                        INNER JOIN  [HQMatajer].[dbo].[Supplier] as suppliers
                        ON items.SupplierID=suppliers.ID
                        where  "+whereQuery;  //I tried with txtQuery.text as well it doesn't work

            SqlCommand cmd = new SqlCommand();



            cmd.Connection = con;
            cmd.CommandText = query;
            con.Open();

            SqlDataAdapter sda = new SqlDataAdapter(cmd);

            sda.Fill(ds);
            //SqlDataReader rd = cmd.ExecuteReader();

            //ASPxGridView1.Columns.Clear();
            ASPxGridView1.AutoGenerateColumns = true;
            ASPxGridView1.DataSource = ds;
            ASPxGridView1.DataBind();
        }
    }

}


protected string getWhereQuery()
{
    string query = txtQuery.Text;
    return query;
}

Answer 1

By default (at first page load) you txtQuery.Text is empty, change your getWhereQuery to:

protected string getWhereQuery()
{
    string query = txtQuery.Text;
    if(string.IsNullOrEmpty(query))
     query=" 1=1";
    return query;
}