Need to update my filtering tools

Question

In my application i have ask my friend to help me with coding the filtering tools but we got stock in some parts, so i need your kind support guys to help me with updating my code below such as "var query = query + " where " + conditions;" also "string conditions = "";" we dont have that big experience in c# so for that i refer to you guys if you need more explanation the below youtube link will give more info please check it
https://www.youtube.com/watch?v=nh5fbBuUeOE
Div  protected void Sortcarbtn_Click(object sender, EventArgs e)         {
if (Session["location"] != null)             {
using (SqlConnection CarsortCon = new SqlConnection(cs))                 {
string maker = (barndcardrlst.SelectedIndex > 0) ? barndcardrlst.SelectedValue : null;                     string yearfrom = (CarYearfrmDrDw.SelectedIndex > 0) ? CarYearfrmDrDw.SelectedValue : null;                     string yearto = (CarYeartoDrDw.SelectedIndex > 0) ? CarYeartoDrDw.SelectedValue : null;                     string gearddl = (GearDrDw.SelectedIndex > 0) ? GearDrDw.SelectedValue : null;                     string CarCond = (CarCondDrDw.SelectedIndex > 0) ? CarCondDrDw.SelectedValue : null;                     string prisfrom = (CarPriceFrmDrDw.SelectedIndex > 0) ? CarPriceFrmDrDw.SelectedValue : null;                     string pristo = (CarPriceToDrDw.SelectedIndex > 0) ? CarPriceToDrDw.SelectedValue : null;                     string Contrddl = (countrdrdolst.SelectedIndex > 0) ? countrdrdolst.SelectedValue : null;                     string statddl = (statedrdolst.SelectedIndex > 0) ? statedrdolst.SelectedValue : null;                     string cityddl = (citiesdrdolst.SelectedIndex > 0) ? citiesdrdolst.SelectedValue : null;
string query = (@"select * from ads where Category = @Category                          AND Country = @Country AND Maker=@brand AND Gear=@G AND Condition=@COND AND Year >@startYear and Year
var location = Convert.ToString(Session["location"]);                     var cat = Convert.ToString(Request.QueryString["cat"]);
string conditions = "";
if (maker != null) conditions += " maker like '%" + maker + "%' ";
if (yearfrom != null) conditions += " and year > " + yearfrom;
if (yearto != null) conditions += " and year
if (gearddl != null) conditions += " and gear = '%" + gearddl + "%' ";
if (CarCond != null) conditions += " Condition = '%" + CarCond + "%' ";
if (prisfrom != null) conditions += " and price > " + prisfrom;
if (pristo != null) conditions += " and price
if (Contrddl != null) conditions += " Country = '%" + Contrddl + "%' ";
if (statddl != null) conditions += " State = '%" + statddl + "%' ";
if (cityddl != null) conditions += " City = '%" + cityddl + "%' ";
var query = query + " where " + conditions;
CarsortQ.Fill(CarsortDataSet);
cateshowlistview.DataSource = CarsortDataSet.Tables[0];                     cateshowlistview.DataBind();
}
}         }

Mike Simo · Answer

hi @ Sumit Jolly
i am trying since long time to code the filtering of my listview and i dont know how i am looking for someone who can help me with coding it, if you watch my youtube link it may gives you an overview of what i am looking for i wish if you can help me by update my coding to be work

Guest User · Answer

what's the issue that you're facing in the code?
any error or not relevant result.